Method for the treatment of keratin materials using acid, ester or amide c-glycoside derivatives, and cosmetic composition containing same

ABSTRACT

The present invention relates to a method for the cosmetic treatment of keratin materials, in particular the skin, comprising the application of a composition to the keratin materials, such as the skin, said composition comprising a compound (I), wherein R is as defined in the description and S* is a mono or polysaccharide. In particular, the invention relates to the non-therapeutic cosmetic use of at least one compound of formula (I) as an agent for whitening, lightening and/or depigmenting keratin materials, such as the skin.

The present invention relates to the field of cosmetic products, moreparticularly intended for caring for keratin materials, especially forcaring for facial and/or bodily skin.

The invention relates to C-glycoside compounds comprising an acid, esteror amide group, to a cosmetic composition comprising same, to apreparation process, to the use of said C-glycosides for treatingkeratin materials and in particular the skin, and to a process fortreating keratin materials using said C-glycosides.

More particularly, the present invention is directed towards proposingthe use of a novel active agent for efficiently depigmenting and/orlightening, or even bleaching, keratin materials, especially facialand/or bodily skin, and/or for improving the complexion, especially itshomogeneity and its radiance.

The colour of human keratin materials, especially of human skin, ismainly determined by the nature and concentration of a pigment, melanin.

The mechanism of melanogenesis, i.e. the mechanism of formation ofmelanin, is particularly complex and, schematically, involves thefollowing main steps:

Tyrosine→Dopa→Dopaquinone→Dopachrome→Melanin

More particularly, tyrosinase is the essential enzyme which regulatesthe first steps in the synthesis of pheomelanin and eumelanin, which arethe two types of melanin.

The pigmentation of facial and/or bodily skin, and more particularly thepigmentation of the skin, depends on various factors such asenvironmental factors associated with the seasons of the year, and theorigin of the individual.

In addition, at various times in their life, certain people develop ontheir skin, and more especially on the hands, darker and/or morecoloured spots, giving the skin heterogeneity. These spots, which areclassified among benign unesthetic pigmentary impairments, are also dueto a high concentration of melanin in the skin.

Many processes, mainly with a cosmetic aim, have thus been developed inorder to attempt to eliminate or reduce the presence of these unestheticbenign pigmentary impairments. The removal or reduction of the presenceof these impairments is customarily founded on applying depigmentingtreatments, based on reducing the activity of melanin synthesis in themelanocytes. Depigmenting molecules are to be distinguished fromanti-pigmenting molecules which limit the action of the stressesresponsible for pigmentation caused, for example, by ultravioletradiation.

More precisely, a molecule is acknowledged as being depigmenting if, inparticular, it interferes with one of the steps of melanin biosynthesiseither by inhibiting one of the enzymes involved in melanogenesis, or byintervening as a structural analog of one of the chemical compounds ofthe melanin synthesis chain, which chain can then be blocked and thusbring about depigmentation.

One of the main routes explored to date is founded on inhibitingtyrosinase. The aim of these treatments is to reduce or even to stop thesynthesis of pigment.

The main depigmenting substances known are hydroquinone and derivativesthereof, in particular ethers thereof such as hydroquinone monomethylether and monoethyl ether, kojic acid, arbutin, etc.

However, there are major drawbacks associated with the use of theabovementioned depigmenting agents. Specifically, the depigmentingsubstances may especially show a certain level of instability, lowefficiency at low concentration, biological activity affecting otherfunctions, etc.

For example, as regards hydroquinone and derivatives thereof, althoughthese compounds have a certain level of efficacy, they are,unfortunately, not free of side effects, which may make them difficultor even hazardous to use. Thus, the use of harmless topical depigmentingsubstances with good efficacy is most particularly sought for thepurpose of efficiently depigmenting and/or lightening, or evenbleaching, keratin materials, especially the skin, and/or forpreventing, reducing and/or treating impairment of the complexion of theskin or of the complexion of semi-mucous membranes, i.e. in particularimproving the homogeneity of the complexion and/or reviving the radianceof the complexion.

The need thus remains for a novel agent for bleaching keratin materials,especially the skin, which also makes it possible especially to improvethe homogeneity of the complexion and to revive the radiance of thecomplexion, the action of which agent is just as efficient as the knownagents, but which does not have the drawbacks thereof, i.e. which isstable, readily formulable, including in aqueous compositions, and/orwhich is efficient even at low concentration.

In this regard, the Applicant Company has, surprisingly andunexpectedly, discovered that certain particular C-glycoside compoundsbearing an acid, ester or amide group have good activity in depigmentingkeratin materials and also an action which makes it possible to prevent,reduce and/or treat an impairment of the complexion of the skin or ofthe complexion of semi-mucous membranes, i.e. in particular an activitywhich makes it possible to improve the homogeneity of the complexion andto revive the radiance of the complexion, even at low concentration.

Women, and men, currently have, furthermore, a tendency to wish toappear youthful for as long as possible and consequently seek to tonedown the signs of ageing of the skin, which are reflected in particularby wrinkles and fine lines, thinning of the epidermis and/or a flaccidand withered skin appearance. In this regard, the advertising andfashion industries mention products for retaining radiant andwrinkle-free skin, signs of youthful skin, for as long as possible, allthe more so since physical appearance has an effect on the psyche and/oron morale.

The skin is constituted of two compartments, a surface compartment, theepidermis, and the other deeper compartment, the dermis, which interact.Natural human epidermis is composed mainly of three types of cells,namely keratinocytes, which form the vast majority, melanocytes andLangerhans cells. Each of these types of cells contributes, by virtue ofits intrinsic functions, to the essential role played in the body by theskin, in particular the role of protecting the body against externalattacking factors, which is known as the “barrier function”.

The epidermis is conventionally divided into a basal layer ofkeratinocytes that constitutes the germinative layer of the epidermis, aspinous layer constituted of several layers of polyhedral cellspositioned on the germinative layers, one to three “granular” layersconstituted of flattened cells containing distinct cytoplasmicinclusions, keratohyalin granules, and finally the cornified layer (orstratum corneum), constituted of a set of layers of keratinocytes at theterminal stage of their differentiation, known as corneocytes.Corneocytes are anuclear cells mainly constituted of a fibrous materialcontaining cytokeratins, surrounded by a cornified envelope.

The dermis provides the epidermis with a solid support. It is also itsnourishing element. It is constituted mainly of fibroblasts and anextracellular matrix composed predominantly of collagen, elastin and asubstance known as ground substance. These components are synthesized bythe fibroblasts. Leukocytes, mast cells or else tissue macrophages arealso found therein. Finally, blood vessels and nerve fibres pass throughthe dermis. The cohesion between the epidermis and the dermis isprovided by the dermo-epidermal junction.

The epidermis is constantly engaged in producing new keratinocytes tocompensate for the continuous loss of epidermal cells at the cornifiedlayer. However, in the course of ageing, a decrease in the number ofcells in the proliferation phase, and consequently a decrease of thelive epidermal layers, may be observed physiologically. By limitingand/or delaying the passing of cells into the differentiation phase, thepool of young cells is maintained.

It is thus important to preserve this pool of proliferative cells, bypreventing or delaying their differentiation, in order to contributetowards delaying the onset of the signs of ageing.

During chronological and/or actinic ageing, the dermis and the epidermisundergo numerous modifications and degradations which are reflected,with age, by flaccidness and a loss of suppleness of the skin.

Among the components degraded (in particular collagen and elastin),proteoglycans (also referred to as PGs) and glycosaminoglycans (alsoreferred to as GAGs) are also adversely affected. Specifically, over thecourse of ageing, the fibroblasts and keratinocytes produce fewer andfewer PGs and GAGs and the synthesis thereof is imperfect. This resultsin significant disorganization: the deposition of GAGs on the proteinbackbone forming the PG is abnormal, which results in a decrease in thetonicity of the tissues and thus a loss of suppleness of the skin, andalso in particular a lower aridity of these PGs for water and thereforea reduction in moisturization of the tissues.

Restoring a normal production of PGs and GAGs by fibroblasts andkeratinocytes contributes partially towards compensating for the loss ofmoisturization of the skin.

Moreover, with age, a decrease in the expression of proteins playing akey role in the maintenance of the barrier function of the skin, such asfilaggrin, membrane transglutaminase or fatty acid desaturase 2 (FADS2),is in particular observed.

The importance of combating the degradation of the various structuralproteins of tissues are therefore understood on reading theaforementioned, and possible routes of action for preventing or limitingthe consequences of skin ageing are in particular the stimulation of thesynthesis of structural molecules of the skin, such as collagen, and inparticular collagen Ill, and also filaggrin, laminin-5, fatty aciddesaturase 2 (FADS2) and/or membrane transglutaminase.

The Applicant has surprisingly demonstrated that certain C-glycosidecompounds comprising an amide group have anti-ageing and/or moisturizingproperties.

A first subject of the invention is a process for treating keratinmaterials, using at least one cosmetic composition comprising at leastone compound of formula (I) below:

and also the solvates thereof such as hydrates, the optical andgeometric isomers and tautomers thereof and the organic or mineral baseor acid salts thereof, in which formula (I):

-   -   S* denotes a monosaccharide sugar radical or denotes a        polysaccharide sugar radical comprising from 2 to 5 saccharide        units, each saccharide unit (the saccharide unit in the case of        a monosaccharide or each saccharide unit in the case of        polysaccharides) comprising one or more hydroxyl groups        optionally substituted with a radical R′ chosen from:        -   i) (C₁-C₆)alkyl; or        -   ii) an acetyl radical;        -   said monosaccharide or polysaccharide radical not being able            to comprise a (hemi)acetal or (hemi)aminal function;        -   said monosaccharide or polysaccharide radical possibly also            comprising one or more amino groups NR_(b)R_(c) with R_(b)            and R_(c), which may be identical or different, representing            a hydrogen atom, or an acetyl group, or a protective group            for the amino function, such as (C₁-C₆)alkyl(thio)carbonyl;        -   said monosaccharide or polysaccharide radical being            connected to the rest of the molecule by a bond between the            C₁ carbon atom of one of the sugars of said monosaccharide            or polysaccharide radical, this bond possibly being α or β            anomeric;    -   R represents a group chosen from:        -   i) hydroxyl; this hydroxyl can be in the form of an alkoxide            O⁺, M⁺ with M⁺ representing a cation such as zinc (Zn²⁺),            manganese (Mn²⁺), copper (Cu²⁺), iron (Fe²⁺, Fe³⁺), sodium            (Na⁺), potassium (K⁻), magnesium (Mg²⁺), calcium (Ca²⁺), or            ammonium; (when R is in the form of an alkoxide, it forms,            with the carbonyl in the alpha position a carboxylate            function COO⁺, M⁺ with M⁺ as previously defined);        -   ii) saturated or unsaturated (C₁-C₁₈)alkoxy;        -   iii) optionally substituted aryloxy, such as phenyloxy or            phenoxy;        -   iv) optionally substituted aryl(C₁-C₆)alkoxy, such as            benzyloxy;            -   v) a radical (B1):

in which:

-   -   R_(l) and Ro, independently of one another, denote a hydrogen        atom or a methyl radical, it being understood that R₁ and R₀        cannot simultaneously denote a methyl radical;    -   w=1 to 10, limits included; or        iv) amino —NR₁R₂ with R₁ and R₂, independently of one another,        representing:    -   for R₁:    -   i) a hydrogen atom;    -   ii) a (C₁-C₁₈)alkyl group;    -   iii) a (C₂-C₁₈)alkenyl group;    -   iv) an aryl(C₁-C₄)alkyl group optionally substituted in        particular with at least one hydroxyl and/or saturated or        unsaturated (C₁-C₄)alkoxy group; or    -   v) an optionally substituted aryl or heteroaryl radical;    -   for R₂:    -   i) a hydrogen atom;    -   ii) a (C₁-C₁₈)alkyl group;    -   iii) a (C₂-C₁₈)alkenyl group;    -   iv) an aryl(C₁-C₄)alkyl group optionally substituted in        particular with at least one hydroxyl and/or saturated or        unsaturated (C₁-C₄)alkoxy group;    -   v) an optionally substituted aryl or heteroaryl radical;    -   vi) a radical (B′1):

-   -   in which:        -   R_(h) and R_(k), independently of one another, denote a            hydrogen atom or a methyl radical, it being understood that            R_(h) and R_(k) cannot simultaneously denote a methyl            radical;        -   y=1 to 10, limits included; or    -   vii) a radical (B′2):

-   -   in which:        -   i=0 or 1;        -   R₄ represents a hydrogen atom or R₄ is chosen from the            radicals (a1) to (a32) described below:

-   -   -   or R₄ can form, with R₁ and the nitrogen atom which bears            R₁, a saturated heterocycle of formula A1, A2 or A3:

-   -   -   R₆ denotes            -   i) a hydroxyl radical —OH;            -   ii) an alkoxide —O⁺, M⁺ with M⁺ representing a cation                such as zinc (Zn²⁺), manganese (Mn²⁺), copper (Cu²⁺),                iron (Fe²⁺, Fe³⁺), or an alkali metal cation such as Na⁺                or K⁺, or an alkaline-earth metal cation such as Mg²⁺ or                Ca²⁺, or an ammonium cation;            -   iii) a saturated or unsaturated (C₁-C₆)alkoxy radical;            -   iv) a radical —NR_(f)R_(g) with R_(f) and R_(g), which                may be identical or different, representing a hydrogen                atom or a (C₁-C₆)alkyl group;

    -   or else R₁ and R₂ form, with the nitrogen atom to which they are        attached, an optionally substituted heterocycloalkyl, such as        piperazino, piperidino or morpholino.

One subject of the invention is a process for treating keratinmaterials, in particular the skin, for depigmenting, lightening and/orbleaching keratin materials, especially facial and/or bodily skin,and/or for preventing, reducing and/or treating an impairment in thecomplexion of the skin or in the complexion of semi-mucous membranesusing at least one compound of formula (I), or at least one cosmeticcomposition comprising at least one compound of formula (I), saidformula (I) being the following formula:

and also the solvates thereof such as hydrates, the optical andgeometric isomers and tautomers thereof and the organic or mineral baseor acid salts thereof, in which formula (I):

-   -   S* denotes a monosaccharide sugar radical or denotes a        polysaccharide sugar radical comprising from 2 to 5 saccharide        units, each saccharide unit (the saccharide unit in the case of        a monosaccharide or each saccharide unit in the case of        polysaccharides) comprising one or more hydroxyl groups        optionally substituted with a radical R′ chosen from:        -   i) (C₁-C₆)alkyl; or        -   ii) an acetyl radical;        -   said monosaccharide or polysaccharide radical not being able            to comprise a (hemi)acetal or (hemi)aminal function;        -   said monosaccharide or polysaccharide radical possibly also            comprising one or more amino groups NR_(b)R_(c) with R_(b)            and R_(c), which may be identical or different, representing            a hydrogen atom, or an acetyl group, or a protective group            for the amino function, such as (C₁-C₆)alkyl(thio)carbonyl;        -   said monosaccharide or polysaccharide radical being            connected to the rest of the molecule by a bond between the            C₁ carbon atom of one of the sugars of said monosaccharide            or polysaccharide radical, this bond possibly being α or β            anomeric;    -   R represents a group chosen from:        -   i) hydroxyl; this hydroxyl can be in the form of an alkoxide            O⁻, M⁺ with M⁺ representing a cation such as zinc (Zn²⁺),            manganese (Mn²⁺), copper (Cu²⁺), iron (Fe²⁺, Fe³⁺), sodium            (Na⁺), potassium (K⁺), magnesium (Mg²⁺), calcium (Ca²⁺), or            ammonium; (when R is in the form of an alkoxide, it forms,            with the carbonyl in the alpha position a carboxylate            function COO⁺, M⁺ with M⁺ as previously defined);        -   ii) saturated or unsaturated (C₁-C₁₈)alkoxy;        -   iii) optionally substituted aryloxy, such as phenyloxy or            phenoxy;        -   iv) optionally substituted aryl(C₁-C₆)alkoxy, such as            benzyloxy;        -   v) a radical (B1):

in which:

-   -   R₁ and Ro, independently of one another, denote a hydrogen atom        or a methyl radical, it being understood that R_(l) and R_(o)        cannot simultaneously denote a methyl radical;    -   w=1 to 10, limits included; or        iv) amino —NR₁R₂ with R₁ and R₂, independently of one another,        representing:    -   for R₁:    -   i) a hydrogen atom;    -   ii) a (C₁-C₁₈)alkyl group;    -   iii) a (C₂-C₁₈)alkenyl group;    -   iv) an aryl(C₁-C₄)alkyl group optionally substituted in        particular with at least one hydroxyl and/or saturated or        unsaturated (C₁-C₄)alkoxy group; or    -   v) an optionally substituted aryl or heteroaryl radical;    -   for R₂:    -   i) a hydrogen atom;    -   ii) a (C₁-C₁₈)alkyl group;    -   iii) a (C₂-C₁₈)alkenyl group;    -   iv) an aryl(C₁-C₄)alkyl group optionally substituted in        particular with at least one hydroxyl and/or saturated or        unsaturated (C₁-C₄)alkoxy group;    -   v) an optionally substituted aryl or heteroaryl radical;    -   vi) a radical (B′1):

-   -   in which:        -   R_(h) and R_(k), independently of one another, denote a            hydrogen atom or a methyl radical, it being understood that            R_(h) and R_(k) cannot simultaneously denote a methyl            radical;        -   y=1 to 10, limits included; or    -   vii) a radical (B′2):

-   -   in which:        -   i=0 or 1;        -   R₄ represents a hydrogen atom or R₄ is chosen from the            radicals (a1) to (a32) described below:

-   -   -   or R₄ can form, with R₁ and the nitrogen atom which bears            R₁, a saturated heterocycle of formula A1, A2 or A3:

-   -   -   R₆ denotes            -   i) a hydroxyl radical —OH;            -   ii) an alkoxide —O⁻, M⁺ with M⁺ representing a cation                such as zinc (Zn²⁺), manganese (Mn²⁺), copper (Cu²⁺),                iron (Fe²⁺, Fe³⁺), or an alkali metal cation such as Na⁺                or K⁺, or an alkaline-earth metal cation such as Mg²⁺ or                Ca²⁺, or an ammonium cation;            -   iii) a saturated or unsaturated (C₁-C₆)alkoxy radical;            -   iv) a radical —NR_(f)R_(g) with R_(f) and R_(g), which                may be identical or different, representing a hydrogen                atom or a (C₁-C₆)alkyl group;

    -   or else R₁ and R₂ form, with the nitrogen atom to which they are        attached, an optionally substituted heterocycloalkyl, such as        piperazino, piperidino or morpholino.

The asterisk “*” denotes the point of attachment of the radical to therest of the compound.

A subject of the present invention is also the cosmetic use of at leastone compound of formula (I) and also solvates thereof such as hydrates,optical, geometrical and tautomeric isomers thereof and/or cosmeticallyacceptable salts thereof, as active agent for depigmenting, lighteningand/or bleaching keratin materials, especially facial and/or bodilyskin, and/or for preventing, reducing and/or treating an impairment inthe complexion of the skin or of the complexion of semi-mucousmembranes.

The inventors have, in point of fact, demonstrated that theabovementioned compounds of formula (I) as defined in the presentinvention have depigmenting, lightening or even bleaching activity onkeratin materials, especially the skin. More particularly, it has beenshown, as detailed in the experimental section below, that thesecompounds of formula (I) reduce melanin synthesis.

In particular, according to this first aspect, the present invention isdirected towards protecting the cosmetic use of at least one compound offormula (I) as defined in the present invention or a solvate thereofsuch as hydrates, optical, geometrical or tautomeric isomers thereofand/or cosmetically acceptable salts thereof, for the treatment of atleast one unesthetic benign pigmented impairment.

Also according to this first aspect, the present invention relates tothe cosmetic use of at least one compound of formula (I) as defined inthe present invention or a solvate thereof such as hydrates, optical,geometrical or tautomeric isomers thereof and/or cosmetically acceptablesalts thereof, for improving the homogeneity of the complexion and/orfor reviving the radiance of the complexion.

Preferably, the present invention relates to the cosmetic use of atleast one compound of formula (IIa), (IIb), (IIc), (IIIa), (IIIb),(IIIc), (IIId) and/or (IIIe) as defined in the present invention below,preferably at least one compound chosen from compounds 1 to 5, and alsothe solvates thereof such as hydrates, the optical, geometrical ortautomeric isomers thereof and/or the cosmetically acceptable saltsthereof, for improving the homogeneity of the complexion and/or forreviving the radiance of the complexion.

The compounds of formula (I) as defined in the present invention or acosmetically acceptable salt thereof are, at the present time, not knownto be used for depigmenting, lightening or even bleaching keratinmaterials, especially the skin, or for improving the homogeneity of thecomplexion, or for reviving the radiance of the complexion.

The present invention is also directed towards protecting anon-therapeutic cosmetic treatment process for depigmenting, lighteningand/or bleaching keratin materials, especially facial and/or bodily skinand/or for preventing, reducing and/or treating an impairment in thecomplexion of the skin or of the complexion of semi-mucous membranes,comprising at least one step which consists in applying to said keratinmaterials and in particular facial and/or bodily skin at least onecomposition comprising at least one compound of formula (I) or a solvatethereof such as hydrates, optical, geometrical or tautomeric isomersthereof and/or cosmetically acceptable salts thereof as defined in thepresent invention.

In one particular embodiment, the present invention is also directedtowards protecting a non-therapeutic cosmetic treatment process fordepigmenting, lightening and/or bleaching keratin materials, especiallyfacial and/or bodily skin, and/or for preventing, reducing and/ortreating an impairment in the complexion of the skin or of thecomplexion of semi-mucous membranes, comprising at least one step whichconsists in applying to said keratin materials and in particular facialand/or bodily skin at least one composition comprising at least onecompound of formula (IIa), (IIb), (IIc), (IIIa), (IIIb), (IIIc), (IIId)and/or (IIIe) as defined in the present invention below, preferably atleast one compound chosen from compounds 1 to 5, and also the solvatesthereof such as hydrates, the optical, geometrical or tautomeric isomersthereof and/or cosmetically acceptable salts thereof.

For the purposes of the present invention, the term “preventing” or“prevention” means reducing, at least partly, the risk of occurrence ofa given phenomenon, i.e., in the present invention, impairment of thecomplexion of the skin or of the complexion of semi-mucous membranes.

A subject of the present invention is also the cosmetic use of aC-glycoside compound of formula (I) as defined below as an anti-ageingagent and/or moisturizing agent.

Another subject of the invention is novel compounds of formula (I) asdefined below.

The compounds of formula (I), and in particular the compounds offormulae (IIa), (IIb), (IIc), (IIIa), (IIIb), (IIIc), (IIId), and/or(IIIe) described below, make it possible to treat keratin materials andin particular the skin, in particular for decreasing and/or delaying thesigns of ageing of the skin and/or skin integuments.

The invention also relates to a process for cosmetic treatment ofkeratin materials, in particular the skin, comprising the application,to said materials, comprising a cosmetic composition comprising at leastone compound of formula (I), or in particular at least one compound offormulae (IIa), (IIb), (IIc), (IIIa), (IIIb), (IIIc), (IIId) and/or(IIIe) described below.

For the purposes of the present invention, the term “keratin materials”is intended to mean the skin and skin integuments.

The term “skin” is intended to mean facial and/or bodily skin or thescalp.

The term “integuments” is intended to mean the eyelashes, the eyebrows,the nails and the hair, in particular the eyelashes and the hair.

According to another particular embodiment of the invention, thecomposition is intended for topical administration to keratin materialssuch as the skin.

The compounds (I), in particular the compounds of formulae (IIa), (IIb),(IIc), (IIIa), (IIIb), (IIIc), (IIId) and/or (IIIe) described below makeit possible in particular to prevent and/or treat the signs of skinageing.

Among the signs of skin ageing, mention is in particular made of a lossof firmness and/or elasticity and/or tonicity and/or suppleness of theskin, the formation of wrinkles and fine lines, expression lines, inparticular on the forehead and in the space between the eyebrows,perioral wrinkles and/or fine lines, and/or slackening in the areaaround the lips, in particular in the top lip area (area between the toplip and the nose), a dull appearance of the complexion, and the paperyappearance of the skin.

The compounds (I), and in particular the compounds of formulae (IIa),(IIb), (IIc), (IIIa), (IIIb), (IIIc), (IIId) and/or (IIIe) describedbelow, advantageously have a glycosaminoglycan-synthesis-stimulatingactivity and thus make it possible to prevent and/or treat the signs ofskin ageing, in particular the loss of firmness and/or of elasticityand/or of tonicity and/or of suppleness of the skin.

The compounds (I), and in particular the compounds of formulae (IIa),(IIb), (IIc), (IIIa), (IIIb), (IIIc), (IIId) and/or (IIIe) describedbelow, also make it possible to prevent and/or treat wrinkles and finelines, in particular of the face and/or of the body, most particularlyof the face and/or of the neck.

The compounds (I), and in particular the compounds of formulae (IIa),(IIb), (IIc), (IIIa), (IIIb), (IIIc), (IIId) and/or (IIIe) describedbelow, also make it possible to maintain and/or stimulate themoisturization and/or combat the drying out of keratin materials such asthe skin and/or to maintain the barrier function.

A subject of the invention is also novel compounds of formula (I) asdefined below, and also the solvates thereof such as hydrates, theoptical, geometrical or tautomeric isomers thereof and/or thecosmetically acceptable salts thereof, in particular and the organic ormineral base or acid salts thereof.

The invention also relates to a process for the cosmetic treatment ofkeratin materials, in particular of the skin, comprising the applicationto said materials, comprising a cosmetic composition comprising at leastone compound of formula (I) or especially at least one compound offormula (IIa), (IIb), (IIc), (IIIa), (IIIb), (IIIc), (IIId) and/or(IIIe) described below.

For the purposes of the present invention, the term “keratin materials”means the skin and its integuments.

The term “skin” means all of the skin of the body, including the scalp,mucous membranes and semi-mucous membranes.

The term “skin integuments” means bodily hairs, the eyelashes, the hairand the nails.

More particularly, the skin of the neckline, of the neck and of theface, the hands and the armpits are considered in the present invention,and in particular the skin of the face.

According to another particular mode of the invention, the compositionis intended for topical administration to keratin materials such as theskin.

Preferably, the hydroxyl radicals of the radical S* are not substitutedor are all substituted with the same group R′ as previously defined, inparticular with an acetyl group.

Preferably, the optional amino group(s) NRbRc of the radical S*denote(s) NHRb with Rb all denoting a hydrogen atom or all denoting anacetyl group.

Preferably, the hydroxyl radicals of the radical S*are not substituted,and the optional amino group(s) NRbRc of the radical S* denote(s) NHRbwith Rb all denoting a hydrogen atom or all denoting an acetyl group.

For the purposes of the present invention and unless otherwiseindicated:

-   -   the saturated or unsaturated and optionally fused rings may also        be optionally substituted;    -   the “alkyl” radicals are saturated, linear or branched,        generally C₁-C₁₈, particularly C₁-C₁₅, hydrocarbon-based        radicals, for instance a C₁-C₁₄ alkyl group, mention may in        particular be made of methyl, ethyl, isopropyl, n-propyl,        n-butyl, t-butyl, isobutyl, secbutyl, pentyl, isopentyl,        neopentyl, n-hexyl, n-heptyl, n-octyl and n-tetradecyl groups;    -   the “alkenyl” radicals are linear or branched, unsaturated        C₂-C₁₈ hydrocarbon-based radicals; preferably comprising one or        more conjugated or unconjugated double bonds, such as ethylene,        propylene, butylene, pentylene, 2-methylpropylene, prenyl and        decylene;    -   the “aryl” radicals are fused or non-fused monocyclic or        polycyclic carbon-based radicals, preferentially comprising from        6 to 30 carbon atoms, and of which at least one ring is        aromatic; the aryl radicals are preferentially chosen from        phenyl, biphenyl, naphthyl, indenyl, anthracenyl and        tetrahydronaphthyl and more particularly aryl denotes phenyl;    -   the “alkoxy” radicals are alkyloxy radicals with alkyl as        previously defined, the alkyl part of the alkoxy generally being        C₁-C₁₈, preferably C₁-C₁₀, more preferentially C₁-C₆, such as        methoxy, ethoxy, propoxy and butoxy; when mention is made of        unsaturated, this implies that the alkoxy group can represent an        alkenyloxy group with alkenyl as previously defined;    -   the “cycloalkyl” radicals are C₄-C₈ cycloalkyl radicals,        preferably cyclopentyl and cyclohexyl radicals; the cycloalkyl        radicals may be substituted cycloalkyl radicals, in particular        substituted with alkyl, alkoxy, carboxylic acid, hydroxyl, amine        and ketone groups;    -   the “heterocycloalkyl” radicals are saturated or partially        unsaturated, nonaromatic heterocyclic radicals comprising from 4        to 8 ring members, which comprise from 1 to 3 heteroatoms, in        particular chosen from oxygen, sulfur and nitrogen, preferably        the morpholino, piperazino and piperidino radicals; the        heterocycloalkyl radicals may be radicals which are substituted,        in particular with alkyl, alkoxy, carboxylic acid, hydroxyl,        amine and ketone groups;    -   the “aryl” or “heteroaryl” radicals can be substituted with at        least one atom or group borne by at least one carbon atom,        chosen from:        -   i) C₁-C₁₀ and preferably C₁-C₈ alkyl, optionally substituted            with one or more radicals chosen from the following            radicals: hydroxyl, optionally unsaturated (C₁-C₄)alkoxy,            (poly)hydroxy(C₂-C₄)alkoxy, acylamino, amino substituted            with two identical or different C₁-C₄ alkyl radicals            optionally carrying at least one hydroxyl group, or it being            possible for the two radicals to form, with the nitrogen            atom to which they are attached, a saturated or unsaturated            and optionally substituted 5- to 7-membered and preferably            5- or 6-membered heterocycle optionally comprising another            heteroatom identical to or different from nitrogen;        -   ii) halogen;        -   iii) hydroxyl;        -   iv) C₁-C₄ alkoxy;        -   v) C₁-C₁₀ alkoxycarbonyl;        -   vi) C₂-C₄ (poly)hydroxyalkoxy;        -   vii) C₂-C₄ alkylcarbonyloxy, preferentially —O-acetyl or            acetyloxy;        -   viii) 5- or 6-membered heterocycloalkyl;        -   ix) 5- or 6-membered heteroaryl, and optionally substituted            with a (C₁-C₄)alkyl radical, preferentially methyl;    -   x) amino substituted with one or two C₁-C₆ alkyl radicals, which        may be identical or different, optionally bearing at least: a)        one hydroxyl group, b) amino optionally substituted with one or        two optionally substituted C₁-C₃ alkyl radicals, said alkyl        radicals possibly forming, with the nitrogen atom to which are        attached, a saturated or unsaturated, optionally substituted        heterocycle comprising from 5 to 7 ring members, optionally        comprising at least one other heteroatom possibly different from        nitrogen, c) a quaternary ammonium group —N⁺R′R″R′″, Q⁻ for        which R′, R″ and R′″, which may be identical or different,        represent a hydrogen atom or a C₁-C₄ alkyl group; and Q⁻        represents the anionic counterion such as the halide, d) a 5- or        6-membered heteroaryl radical, and optionally substituted with a        (C₁-C₄) alkyl radical, preferentially methyl;        -   xi) acylamino (—N(R)—C(O)—R′) in which the R radical is a            hydrogen atom or a C₁-C₄ alkyl radical optionally bearing at            least one hydroxyl group and the R′ radical is a C₁-C₂ alkyl            radical;        -   xii) carbamoyl ((R)₂N—C(O)—) in which the R radicals, which            may be identical or different, represent a hydrogen atom or            a C₁-C₄ alkyl radical optionally bearing at least one            hydroxyl group;        -   xiii) alkylsulfonylamino (R′S(O)₂—N(R)—) in which the            radical R represents a hydrogen atom or a C₁-C₄ alkyl            radical optionally bearing at least one hydroxyl group and            the radical R′ represents a C₁-C₄ alkyl radical, or a phenyl            radical;        -   xiv) aminosulfonyl ((R)₂N—S(O)₂—) in which the R radicals,            which may be identical or different, represent a hydrogen            atom or a C₁-C₄ alkyl radical optionally bearing at least            one hydroxyl group;        -   xv) carboxyl in acid or salified form (preferably with an            alkali metal or a substituted or unsubstituted ammonium);        -   xvi) cyano;        -   xvii) benzyloxycarbonyl;        -   xviii) polyhaloalkyl, preferentially trifluoromethyl;        -   xix) a phenylcarbonyloxy group optionally substituted with            one or more hydroxyl groups; and        -   xx) a phenyl group optionally substituted with one or more            hydroxyl groups;    -   the “heteroaryl” radicals are radicals comprising, in at least        one ring, one or more heteroatoms chosen in particular from O, N        and S, preferably O or N, optionally substituted in particular        with one or more alkyl, alkoxy, carboxyl, hydroxyl, amine or        ketone groups, and at least one ring of which is aromatic. These        rings may comprise one or more oxo groups on the carbon atoms of        heteroaryl; mention may in particular be made, among the        heterocyclic radicals that may be used, of furyl, pyranyl,        pyrrolyl, imidazolyl, pyrazolyl, pyridyl thienyl, and        pyrimidinyl groups; optionally, the heterocyclic groups are        fused groups, such as benzofuranyl, chromenyl, xanthenyl,        indolyl, isoindolyl, quinolyl, isoquinolyl, chromanyl,        isochromanyl, indolinyl, isoindolinyl, coumarinyl or        isocoumarinyl groups, it being possible for these groups to be        substituted, in particular with one or more OH groups;    -   the “protective group” or “PG” of the “hydroxyl” or “amino”        function is known by those skilled in the art; mention may be        made of the two books “Protective Groups in Organic        Synthesis”, T. W. Greene, published by John Wiley & Sons, N Y,        1981, pp. 193-217; “Protecting Groups”, P. Kocienski, Thieme,        3^(rd) ed., 2005.    -   In particular, the protective group is chosen from:        -   (C₁-C₆)alkyl(thio)carbonyl such as formyl, acetyl or            t-butylcarbonyl;        -   (di)(tri)halo(C₁-C₆)alkyl(thio)carbonyl such as            trifluoroacetyl (TFA);        -   (C₁-C₆)alkoxy(thio)carbonyl such as methoxycarbonyl,            ethoxycarbonyl, isobutyloxycarbonyl, t-butyloxycarbonyl            (BOC), vinyloxycarbonyl, allyloxycarbonyl;        -   (di)(tri)halo(C₁-C₆)alkoxy(thio)carbonyl such as            2,2,2-trichloroethylcarbonyl;        -   (C₁-C₆)alkylthio-thiocarbonyl;        -   (di)(tri)halo(C₁-C₆)alkylthiothiocarbonyl;        -   (di)(C₁-C₆)(alkyl)aminocarbonyl;        -   (di)(C₁-C₆)(alkyl)aminothiocarbonyl;        -   optionally substituted arylcarbonyl such as phenylcarbonyl            or 2,4,6-trimethylphenylcarbonyl;        -   optionally substituted aryloxycarbonyl such as            p-nitrophenoxycarbonyl;        -   optionally substituted aryl(C₁-C₆)alkoxycarbonyl such as            benzyloxycarbonyl or Cbz, p-methoxybenzyloxycarbonyl,            3,4-dimethoxybenzyloxycarbonyl, onitrobenzyloxycarbonyl,            p-nitrobenzyloxycarbonyl, 2-bromobenzyloxycarbonyl            (2-bromo-Z) and 2-chlorobenzyloxycarbonyl (2-chloro-Z),            4-nitrobenzyloxycarbonyl (nitro-Z),        -   heteroaryl(C₁-C₆)alkoxycarbonyl such as            9-fluorenylmethoxycarbonyl (FMOC) or nicotinoyl;        -   (di)(C₁-C₆)(alkyl)aminocarbonyl, for instance            dimethylaminocarbonyl;        -   (C₁-C₆)(alkyl)arylaminocarbonyl;        -   carboxyl;        -   optionally substituted aryl such as phenyl, dibenzosuberyl            or 1,3,5-cycloheptatrienyl;        -   optionally substituted heteroaryl; in particular including            the following cationic or non-cationic heteroaryls            comprising from 1 to 4 heteroatoms:            i) 5-, 6- or 7-membered monocyclic groups such as furanyl or            furyl, pyrrolyl or pyrryl, thiophenyl or thienyl, pyrazolyl,            oxazolyl, oxazolium, isoxazolyl, isoxazolium, thiazolyl,            thiazolium, isothiazolyl, isothiazolium, 1,2,4-triazolyl,            1,2,4-triazolium, 1,2,3-triazolyl, 1,2,3-triazolium,            1,2,4-oxazolyl, 1,2,4-oxazolium, 1,2,4-thiadiazolyl,            1,2,4-thiadiazolium, pyrylium, thiopyridyl, pyridinium,            pyrimidinyl, pyrimidinium, pyrazinyl, pyrazinium,            pyridazinyl, pyridazinium, triazinyl, triazinium,            tetrazinyl, tetrazinium, azepine, azepinium, oxazepinyl,            oxazepinium, thiepinyl, thiepinium, imidazolyl, imidazolium;            ii) 8- to 11-membered bicyclic groups such as indolyl,            indolinium, benzimidazolyl, benzimidazolium, benzoxazolyl,            benzoxazolium, dihydrobenzoxazolinyl, benzothiazolyl,            benzothiazolium, pyridoimidazolyl, pyridoimidazolium,            thienocycloheptadienyl, these monocyclic or bicyclic groups            being optionally substituted with one or more groups such as            (C₁-C₄)alkyl, for instance methyl, or polyhalo(C₁-C₄)alkyl,            for instance trifluoromethyl;            iii) or the following tricyclic ABC group:

in which the two rings A and C optionally comprise a heteroatom, andring B is a 5-, 6- or 7-membered ring, particularly a 6-membered ring,and contains at least one heteroatom, for instance piperidyl or pyranyl;

-   -   optionally cationic, optionally substituted heterocycloalkyl,        the heterocycloalkyl group in particular representing a        saturated or partially saturated 5-, 6- or 7-membered monocyclic        group comprising from 1 to 4 heteroatoms chosen from oxygen,        sulfur and nitrogen, such as di/tetrahydrofuranyl,        di/tetrahydrothiophenyl, di/tetrahydropyrrolyl,        di/tetrahydropyranyl, di/tetra/hexahydrothiopyranyl,        dihydropyridyl, piperazinyl, piperidinyl,        tetramethylpiperidinyl, morpholinyl, di/tetra/hexahydroazepinyl,        di/tetrahydropyrimidinyl, these groups being optionally        substituted with one or more groups such as (C₁-C₄)alkyl, oxo or        thioxo, preferably tetrahydropyranyl THP; or the heterocycle        represents the following group:

in which R′^(c), R′^(d), R′^(e), R′^(f), R′^(g) and R′^(h), which may beidentical or different, represent a hydrogen atom or a (C₁-C₄)alkylgroup, or alternatively two groups R′^(g) with R′^(h), and/or R′^(e)with R′^(f) form an oxo or thioxo group, or alternatively R′^(g) withR′^(e) together form a cycloalkyl; and v represents an integer between 1and 3 inclusive; preferentially, R′^(c) to R′^(h) represent a hydrogenatom; and An⁻ represents a counterion;

-   -   isothiouronium —C(NR′^(c)R′^(d))═N⁺R′^(e)R′^(f); An⁻ with        R′^(c), R′^(d), R′^(e) and R′^(f), which may be identical or        different, representing a hydrogen atom or a (C₁-C₄)alkyl group;        preferentially, R′^(c) to R′^(f) represent a hydrogen atom; and        An⁻ represents a counterion;    -   isothiourea —C(NR′^(c)R′^(d))═NR′^(e); with R′^(c), R′^(d) and        R′^(e) as previously defined;    -   optionally substituted (di)aryl(C₁-C₄)alkyl or        triaryl(C₁-C₄)alkyl such as 9-anthracenylmethyl, phenylmethyl        (benzyl), diphenylmethyl or triphenylmethyl optionally        substituted with one or more groups, in particular chosen from        halogen, (C₁-C₄)alkyl, (C₁-C₄)alkoxy such as methoxy, hydroxyl,        (C₁-C₄)alkylcarbonyl, (di)(C₁-C₄)(alkyl)amino such as        dimethylamino, nitro;    -   optionally substituted (di)heteroaryl(C₁-C₄)alkyl or        triheteroaryl(C₁-C₄)alkyl, the heteroaryl group in particular        being cationic or noncationic, 5- or 6-membered monocyclic        comprising from 1 to 4 heteroatoms chosen from nitrogen, oxygen        and sulfur, such as pyrrolyl, furanyl, thiophenyl, pyridyl,        pyridyl N-oxide such as 4-pyridyl or 2-pyridyl-N-oxide,        pyrylium, pyridinium or triazinyl groups, optionally substituted        with one or more groups such as alkyl, particularly methyl;        advantageously, the (di)heteroaryl(C₁-C₄)alkyl is        (di)heteroarylmethyl or (di)heteroarylethyl;    -   CR¹R²R³ with R¹, R² and R³, which may be identical or different,        representing a halogen atom, such as (tri)(di)halo(C₁-C₄)alkyl        such as 2,2,2-trichloroethyl or a group chosen from:        -   (C₁-C₄)alkyl such as methyl;        -   (C₁-C₄)alkoxy;        -   optionally substituted aryl such as phenyl optionally            substituted with one or more groups, for instance            (C₁-C₄)alkyl, (C₁-C₄)alkoxy or hydroxyl;        -   optionally substituted heteroaryl such as thiophenyl,            furanyl, pyrrolyl, pyranyl or pyridyl, optionally            substituted with a (C₁-C₄)alkyl group;        -   P(Z′)R′¹R′²R′³ with R′¹ and R′², which may be identical or            different, representing a hydroxyl, (C₁-C₄)alkoxy or alkyl            group, R′³ representing a hydroxyl or (C₁-C₄)alkoxy group,            and Z¹ representing an oxygen or sulfur atom;    -   (C₂-C₆)alkylene, in particular allyl H₂C═CH—CH₂—;    -   optionally substituted arylsulfonyl such as p-toluenesulfonyl        (Tos);    -   sterically hindered cycloalkyl such as the adamantyl group;    -   sterically hindered cycloalkyloxy(thio)carbonyl such as        1-adamantyloxycarbonyl (Adoc) or        1-(adamantyl)-1-methylethoxycarbonyl (Adpoc);    -   optionally substituted (C₁-C₄)alkoxy(C₁-C₄)alkyl such as        methoxymethyl (MOM), ethoxyethyl (EOM) and isobutoxymethyl;    -   (tri)(di)halo(C₁-C₄)alkyl such as 2,2,2-trichloroethyl;    -   R_(e)R_(f)R_(g)Si— with R_(e), R_(f), and R_(g), which may be        identical or different, representing a (C₁-C₆)alkyl group,        optionally substituted aryl group, optionally substituted        (di)aryl(C₁-C₄)alkyl group, optionally substituted        triaryl(C₁-C₄)alkyl group, such as benzyl, in particular chosen        from trimethylsilyl or TMS, triethylsilyl,        isopropyldimethylsilyl, tert-butyldimethylsilyl or TBDMS,        (triphenylmethyl)dimethylsilyl, tbutyldiphenylsilyl,        methyldiisopropylsilyl, methyl(di-t-butyl)silyl, tribenzylsilyl,        trip-xylylsilyl, triisopropylsilyl, triphenylsilyl;    -   or else two contiguous hydroxyl groups can be protected with an        alkylene group *—C(R^(l))(R^(m))—(C(R^(k))(R^(j))_(q)—* as drawn        below:

-   -   with R^(j), R^(k), R^(l), and R^(m), which may be identical or        different, representing a hydrogen atom or a (C₁-C₄)alkyl,        (poly)halo(C₁-C₄)alkyl, optionally substituted aryl such as        phenyl, aryl(C₁-C₄)alkyl such as benzyl,        (poly)halo(C₁-C₄)alkoxy, (C₁-C₄)alkoxy, halogen,        (di)(C₁-C₄)(alkyl)amino or hydroxyl group, or else two R^(j) and        R^(k) and/or R^(l), and R^(m) groups form, together with the        carbon atom which bears them, an oxo group or a        (hetero)cycloalkyl group such as cyclohexyl or cyclopropyl; q is        0, 1, 2 or 3, preferably        *—C(R^(l))(R^(m))—(C(R^(k))(R^(j)))_(q)—* represents a        methylene, ethylene, propylene, dimethylmethylene, *—C(CH₃)₂—*        or diphenylmethylene *—C(Ph)₂-*, cyclopentylidene,        cyclohexylidene, cycloheptylidene, benzylidene,        p-methoxybenzylidene, 2,4-dimethoxybenzylidene, methoxymethylene        and ethoxymethylene.

The asterisk “*” denotes the point of attachment of the radical to therest of the compound.

In the context of the present invention, the sugar radicals, whetherthey are monosaccharide or polysaccharide radicals, do not contain anacetal group or a hemiacetal group or an aminal group or a hemiaminalgroup.

The acceptable solvates of the compounds used in the present inventioncomprise conventional solvates such as those formed during the last stepof the preparation of said compounds due to the presence of solvents.Mention may be made, by way of example, of the solvates due to thepresence of water (hydrates) or of linear or branched alcohols, such asethanol or isopropanol.

The salts of the compounds (I) which comprise at least one acid functioncan be chosen from metal salts, for example aluminium (Al³⁺), zinc(Zn²⁺), manganese (Mn²⁺) or copper (Cu²⁺); alkali metal salts, forexample lithium (Li⁺), sodium (Na⁺) or potassium (K⁻); or alkaline-earthmetal salts, for example calcium (Ca²⁺) or magnesium (Mg²⁺). They canalso be ammonium derivatives of formula NH₄ ⁺ or organic salts such asammonium's of formula Y₃NH⁺, NY₃ denoting an organic amine, the Yradicals being identical or different, it being possible for two orthree Y radicals to form, in pairs, a ring with the nitrogen atom whichcarries them or it being possible for NY₃ to denote an aromatic amine.The organic amines are for example alkylamines, for instancemethylamine, dimethylamine, trimethylamine, triethylamine or ethylamine,or hydroxyalkylamines, for instance 2-hydroxyethylamine,bis(2-hydroxyethyl)amine or tri-(2-hydroxyethyl)amine, orcycloalkylamines, for instance bicyclohexylamine or glucamine,piperidine, or pyridines and the like, for example collidine, quinine orquinoline, or amino acids which are basic in nature, for instance lysineor arginine.

The salts of the compounds of formula (I) which comprise at least oneamine function can be salts of an organic acid such as citric acid,lactic acid, tartaric acid, aspartic acid, glutamic acid, acetic acid,formic acid, trifluoroacetic acid, hydrochloric acid, glycolic acid ormalic acid.

In the case where the compounds according to the invention are in saltform, the cations are of course in an amount which ensures theelectro-neutrality of the compounds of formula (I).

The salts of the compounds of formula (I) which contain at least oneacid function can advantageously be chosen from the metal salts Cu²⁺,Mn²⁺ and Zn²⁺, the alkali metal salts Li⁺, Na⁺ and K⁺ and thealkaline-earth metal salts Ca²⁺ and Mg^(2+.)According to anothervariant, the salts of the compounds of formula (I) according to theinvention which comprise at least one acid function can advantageouslybe chosen from ammoniums, preferably from the salts of amino acids whichare basic in nature, for instance lysine or arginine or fromdiethanolamine salts or triethanolamine salts.

Preferably, the compounds (I) which comprise at least one acid functionare in the form of sodium salts Na⁺.

Preferably, the compounds (I) which comprise at least one acid functionare in the form of potassium salts K⁺.

Preferably, the compounds (I) which comprise at least one acid functionare in the form of calcium salts Ca⁺.

According to one particular embodiment of the invention, the compoundsof formula (I) are such that R represents a hydroxyl radical or analkoxide radical O⁻, M⁺ with M⁺ representing a cation such as zinc(Zn²⁺), manganese (Mn²⁺), copper (Cu²⁺), iron (Fe²⁺, Fe³⁺), sodium(Na⁺), potassium (K⁻), magnesium (Mg²⁺), calcium (Ca²⁺), or ammonium.

As an example of compounds of formula (I) according to this embodiment,mention may particularly be made of the following compound and also thesalts, isomers and solvates thereof:

According to another particular embodiment of the invention, thecompounds of formula (I) are such that R represents a preferablysaturated (C₁-C₁₈)alkoxy group, more preferentially a (C₁-C₆)alkoxygroup, in particular ethoxy.

According to another particular embodiment of the invention, thecompounds of formula (I) are such that, taken together or separately, Rrepresents a radical (B1):

in which:

-   -   R_(l) and Ro, independently of one another, denote a hydrogen        atom or a methyl radical, it being understood that R_(l) and        R_(o) cannot simultaneously denote a methyl radical;    -   w=1 to 10, preferably from 1 to 5, more preferentially from 1 to        3, limits included.

According to another particular embodiment of the invention, thecompounds of formula (I) are such that, taken together or separately, Rrepresents an amino group —NR₁R₂ with R₁ and R₂, independently of oneanother, representing:

-   -   i) a hydrogen atom;    -   ii) a (C₁-C₁₈)alkyl group, preferably (C₁-C₁₆)alkyl such as        (C₁-C₄)alkyl and/or (C₈-C₁₆)alkyl;    -   iii) or else R₁ and R₂ form, with the nitrogen atom to which        they are attached, an optionally substituted heterocycloalkyl,        such as piperazino, piperidino or morpholino.

According to this embodiment, R₁ and R₂ preferably represent,independently of one another:

-   -   i) a hydrogen atom;    -   ii) a (C₁-C₁₈)alkyl group, preferably (C₁-C₁₆)alkyl and in        particular a methyl or n-tetradecyl radical.

According to a first form of this embodiment, R₁ and R₂ are identicaland chosen from

-   -   i) a hydrogen atom;        -   ii) a (C₁-C₁₈)alkyl group, preferably (C₁-C₄)alkyl and in            particular a methyl radical.

As an example of a compound of formula (I) according to this embodiment,mention may for example be made of the compounds below, and also thesalts, isomers and solvates thereof:

According to a second form of this variant, R₁ denotes a hydrogen atomand R₂ denotes a (C₁-C₁₈)alkyl group, preferably (C₁-C₁₆)alkyl and inparticular a (C₈-C₁₆)alkyl radical such as n-tetradecyl.

By way of example of compound of formula (I) according to thisembodiment, mention may be made, for example, of compound 5 below, andalso the salts, isomers or solvates thereof:

According to another particular embodiment of the invention, thecompounds of formula (I) are such that, taken together or separately, Rrepresents an amino group —NR₁R₂ with R₁ and R₂, independently of oneanother, representing:

-   -   for R₁:    -   i) a hydrogen atom; or    -   ii) a (C₁-C₁₈)alkyl group, preferably (C₁-C₄)alkyl; more        preferentially methyl; preferably, R₁ represents a hydrogen        atom;    -   for R₂:    -   a radical (B′1) such as:

-   -   in which:        -   R_(h) and R_(k), independently of one another, denote a            hydrogen atom or a methyl radical, it being understood that            R_(h) and R_(k) cannot simultaneously denote a methyl            radical;        -   y=1 to 10, preferably from 1 to 5, more preferentially from            1 to 3, limits included.

According to another particular embodiment of the invention, thecompounds of formula (I) are such that, taken together or separately, Rrepresents an amino group —NR₁R₂ with R₁ and R₂, independently of oneanother, representing:

-   -   for R₁:    -   i) a hydrogen atom; or    -   ii) a (C₁-C₁₈)alkyl group, preferably (C₁-C₄)alkyl; more        preferentially methyl; preferably, R₁ represents a hydrogen        atom;    -   for R₂:    -   a radical (B′2):

-   -   in which:        -   i=0 or 1;        -   R₄ represents a hydrogen atom or R₄ is chosen from the            radicals (a1) to (a32) described below:

-   -   -   or R₄ can also form, with R₁ and the nitrogen atom which            bears R₁, a saturated heterocycle of formula A1, A2 or A3:

-   -   -   R₆ denotes            -   i) a hydroxyl radical —OH;            -   ii) an alkoxide —O⁻, M⁺ with M⁺ representing a cation                such as zinc (Zn²⁺), manganese (Mn²⁺), copper (Cu²⁺),                iron (Fe²⁺, Fe³⁺), or an alkali metal cation such as Na⁺                or K⁺, or an alkaline-earth metal cation such as Mg²⁺ or                Ca²⁺, or an ammonium cation;            -   iii) a saturated or unsaturated (C₁-C₆)alkoxy radical;                or            -   iv) a radical —NR_(f)R_(g) with R_(f) and R_(g), which                may be identical or different, representing a hydrogen                atom or a (C₁-C₆)alkyl group.

According to another particular embodiment of the invention, thecompounds of formula (I) are such that, taken together or separately, Rrepresents an amino group —NR₁R₂ with R₁ and R₂, independently of oneanother, representing:

-   -   for R₁:    -   i) a hydrogen atom;    -   ii) a (C₁-C₁₈)alkyl group, preferably (C₁-C₄)alkyl; more        preferentially methyl; and preferably R₁ represents a hydrogen        atom;    -   for R₂:    -   i) an optionally substituted aryl or heteroaryl radical, in        particular an optionally substituted phenyl radical;    -   iii) an optionally substituted heteroaryl radical;    -   iv) an aryl(C₁-C₄)-alkyl radical, in particular a        phenyl-(C₁-C₄)alkyl radical; and preferably R₂ denotes an        optionally substituted phenyl radical.

According to another particular embodiment of the invention, thecompounds of formula (I) are such that, taken together or separately, Rrepresents an optionally substituted aryloxy group, in particular anoptionally substituted phenoxy group.

According to another particular embodiment of the invention, thecompounds of formula (I) are such that, taken together or separately, Rrepresents an optionally substituted aryl(C₁-C₆)alkoxy group, such as anoptionally substituted benzyloxy group.

It is understood that, for the compounds of formula (I) as previouslydefined, when S* represents a monosaccharide radical, then it can be inpyranose form (the sugar heterocycle which constitutes it comprises 6ring members) or furanose form (the sugar heterocycle which constitutesit comprises 5 ring members); and when S* represents a polysaccharideradical, it comprises the sequence of 2 to 5 saccharide units, which maybe identical to or different from one another, which may be in furanoseor pyranose form. Preferably, when S* represents a polysaccharideradical, the polysaccharide is a disaccharide which results from thelinking of 2 pyranose units or the linking of a saccharide unit infuranose form and a unit in pyranose form or the linking of a saccharideunit in pyranose form and a unit in furanose form; whether it is for themonosaccharide or polysaccharide radical, each saccharide unit may be inlevorotatory L or dextrorotatory D form, and in α or β anomeric form.

According to one preferred embodiment, the sugar radical S* represents amonosaccharide radical in which the heterocycle constituting it contains4 or 5 carbon atoms, of formula S*′ below:

R_(s) representing a hydrogen atom, a (C₁-C₄)alkyl group such as methylor a (poly)hydroxy(C₁-C₄)alkyl group such as hydroxymethyl or1,2-dihydroxyethyl, the hydroxyl function(s) of the(poly)hydroxy(C₁-C₄)alkyl group being substituted with A as definedbelow;it being understood that the R_(a) radical is in the C₅ position if thesugar unit is in pyranose form or in the C₄ position if it is infuranose form;R_(b) representing a hydrogen atom or a (C₁-C₄)alkyl group, preferablyhydrogen;R_(c) representing a hydrogen atom, or a protective group for the aminefunction, such as R_(d)—C(O)—, identical in the case of several hydroxylfunctions, with R_(d) representing a(C₁-C₄)alkyl group, R_(c) preferablyrepresenting an acetyl group CH₃—C(O)—;R_(e) representing a hydrogen atom or a —CH₂—O-A group;A representing a hydrogen atom, a (C₁-C₆)alkyl group or ahydroxyl-function-protective group, such as R_(d)—C(O)— as defined aboveand in particular acetyl CH₃—C(O)—, or else, when n is greater than orequal to 2 and two groups A-O are contiguous, then two A groups cantogether form a linear or branched (C₁-C₆)alkylene chain;preferably, all the protective groups for A are identical;n is equal to 1, 2 or 3 and m is equal to 0 or 1.

According to a particular form of the invention, m is zero.

According to another preferred embodiment, the sugar radical S*represents a polysaccharide radical constituted of 2 to 5 saccharideunits, in particular of 2 to 3 and preferably of 2 saccharide units,linked together via an oxygen atom (oxy), of 1-4 (C₁ of one saccharideunit→C₄ of the other saccharide unit) or 1-3 (C₁ of one saccharideunit→C₃ of the other saccharide unit) or 1-6 (C₁ of one saccharideunit→C₆ of the other saccharide unit), each saccharide unit of which isconstituted of a heterocycle comprising 4 or 5 carbon atoms, of formulaS*″ below:

in which formula S*″, p and q represent integers of inclusively between0 and 4 with p+q inclusively between 1 and 4, particularly between 1 and2, preferentially p+q=1; R_(a), which may be identical or different, areas defined previously, R_(b), which may be identical or different, areas defined previously, R_(c), which may be identical or different, areas defined previously, R_(e), which may be identical or different, areas defined previously, A, which may be identical or different, are asdefined previously, m, which may be identical or different, are asdefined previously, n, which may be identical or different, are asdefined previously, it being understood that the two sugar units betweenthe square brackets q and p can interchange, i.e. can represent thechain below:

According to one preferred variant of the invention, the compounds offormula (I) are such that:

-   -   S* represents a monosaccharide sugar radical, in pyranose or        furanose form, said monosaccharide being chosen from: glucose,        galactose, mannose, xylose, lyxose, fucose, arabinose, rhamnose,        quinovose, fructose, sorbose, talose, N-acetylglucosamine,        N-acetylgalactosamine, glucosamine and galactosamine; or S*        represents a disaccharide chosen from: lactose, maltulose,        palatinose, lactulose, amygdalose, turanose, cellobiose,        isomaltose, rutinose and maltose, preferably S* represents a        sugar radical chosen from glucose, galactose, mannose, xylose,        rhamnose, fructose, sorbose, N-acetylglucosamine,        N-acetylgalactosamine, glucosamine, galactosamine, lactose,        cellobiose and maltose, and preferably chosen from glucose,        xylose and rhamnose;        -   said radical S* comprising one or more radicals —OR, and            optionally one or two radicals —NHR′_(s),        -   said monosaccharide or disaccharide radical being connected            to the rest of the molecule by a bond between the C′ carbon            atom of the sugar or one of the sugars and this bond            possibly being α or β anomeric;    -   R represents:        -   i) a hydroxyl radical; can be in carboxylate form O⁺, M⁺            with M⁺ representing a cation such as zinc (Zn²⁺), manganese            (Mn²⁺), copper (Cu²⁺), iron (Fe²⁺, Fe³⁺), sodium (Na⁺),            potassium (K⁻), magnesium (Mg²⁺), calcium (Ca²⁺), or            ammonium;        -   ii) a (C₁-C₁₈)alkoxy group, preferably (C₂-C₆)alkoxy such as            ethoxy;        -   iii) a (C₂-C₁₈)alkenyloxy, preferably (C₂-C₆)alkenyloxy,            such as prenyloxy;        -   iv) an optionally substituted aryloxy radical, such as            phenyloxy or phenoxy;        -   v) an aryl(C₁-C₆)alkoxy radical optionally substituted in            particular with at least one hydroxyl and/or saturated or            unsaturated (C₁-C₄)alkoxy group, in particular an            aryl(C₁-C₄)alkoxy radical such as benzyloxy;        -   v) a radical such as:

-   -   -   in which:        -   R_(l) and Ro, independently of one another, denote a            hydrogen atom or a methyl radical, it being understood that            R_(l) and R_(o) cannot simultaneously denote a methyl            radical;        -   w=1 to 10, preferably 1 to 5, preferentially from 1 to 3,            limits included.        -   vi) an amino radical —NR₁R₂ with R₁ and R₂, independently of            one another, representing:        -   for R₁:            -   a hydrogen atom;            -   a saturated or unsaturated (C₁-C₁₈)alkyl group, which is                preferably saturated and more preferentially a saturated                C₁-C₆ group such as methyl;        -   for R₂:            -   a hydrogen atom;            -   a saturated or unsaturated (C₁-C₁₈)alkyl group, which is                preferably saturated and more preferentially a saturated                C₁-C₆ group such as methyl;            -   an aryl(C₁-C₄)alkyl group optionally substituted in                particular with at least one hydroxyl and/or saturated                or unsaturated (C₁-C₄)alkoxy group;            -   an aryl or heteroaryl radical, which is optionally                substituted, preferably with one or more (C₁-C₆)alkyl,                hydroxyl, C₁-C₄ alkoxy, C₁-C₆ alkoxycarbonyl, or carboxy                groups, which may be identical or different;            -   a radical such as:

-   -   -   in which:            -   R_(h) and R_(k), independently of one another, denote a                hydrogen atom or a methyl radical, it being understood                that R_(h) and R_(k) cannot simultaneously denote a                methyl radical;            -   y=1 to 10, preferably 1 to 5, preferentially from 1 to                3;        -   a radical such as:

-   -   -   in which:            -   i=0 or 1;                R₄ represents a hydrogen atom or a radical R₄ chosen                from the radicals (a1) to (a32) described below

-   -   R₄ can also form, with R₁ and the nitrogen atom which bears R₁,        a saturated heterocycle of formula A1 or A2 or A3:

-   -   R₆ denotes        -   i) a hydroxyl radical —OH;        -   ii) an alkoxide —O⁻, M⁺ with M⁺ representing a cation such            as zinc (Zn²⁺), manganese (Mn²⁺), copper (Cu²⁺), iron (Fe²⁺,            Fe³⁺), or an alkali metal cation such as Na⁺ or K⁺, or an            alkaline-earth metal cation such as Mg²⁺ or Ca²⁺, or an            ammonium cation;        -   iii) a saturated or unsaturated (C₁-C₆)alkoxy radical;        -   iv) a radical —NR_(f)R_(g) with R_(f) and R_(g), which may            be identical or different, representing a hydrogen atom or a            (C₁-C₆)alkyl group.        -   or else R₁ and R₂ form, with the nitrogen atom to which they            are attached, an optionally substituted heterocycloalkyl,            such as piperazino, piperidino or morpholino.    -   R_(s) represents a hydrogen atom or a methyl radical or an        acetyl radical;        -   said radicals R_(s) preferably all being identical and all            preferably denoting a hydrogen atom or an acetyl radical;    -   R′_(s) represents a radical chosen from a hydrogen atom or an        acetyl radical.

More preferentially, the compounds of formula (I) are chosen from thecompounds of formulae (I′), (I″), (I″″), (I′a), (I″a), (I″″a) and (I′b)below:

and also the solvates thereof such as hydrates, the optical andgeometric isomers and tautomers thereof and the organic or mineral baseor acid salts thereof, in which formulae (I′), (I″), (I″″), (I′a),(I″a), (I″″a) and (I′b):

-   -   R is as previously defined, and preferably represents one of the        following groups:        -   i) hydroxyl; this hydroxyl can be in the form of an alkoxide            O⁻, M⁺ with M⁺ representing a cation such as zinc (Zn²⁺),            manganese (Mn²⁺), copper (Cu²⁺), iron (Fe²⁺, Fe³⁺), sodium            (Na⁺), potassium (K⁺), magnesium (Mg²⁺), calcium (Ca²⁺), or            ammonium; (when R is in the form of an alkoxide, it forms,            with the carbonyl in the alpha position a carboxylate            function COO⁺, M⁺ with M⁺ as previously defined);        -   ii) (C₁-C₁₈)alkoxy; preferably C₁-C₄ alkoxy and more            preferentially ethoxy;        -   iii) amino —NR′₁R′₂ with R′₁ and R′₂, independently of one            another, representing:            -   for R′₁:                -   i) a hydrogen atom;                -   ii) a (C₁-C₁₈)alkyl group, preferably (C₁-C₆)alkyl,                    preferentially a methyl;            -   for R′₂:                -   i) a hydrogen atom;                -   ii) a (C₁-C₅₈)alkyl group;                -   iii) a radical such as:

-   -   -   -   -   in which:

            -   j=0 or 1;

        -   R′₄ represents a hydrogen atom or R′₄ is chosen from the            radicals (a1) to (a32) described below:

-   -   -   -   R′₄ can also form, with R′₁ and the nitrogen which bears                R′₁, a saturated heterocycle of formula A1 or A2 or A3:

-   -   -   -   R′₆ denotes                -   i) a hydroxyl radical —OH;                -   ii) an alkoxide —O⁻, M⁺ with M⁺ representing a                    cation such as zinc (Zn²⁺), manganese (Mn²⁺), copper                    (Cu²⁺), iron (Fe²⁺, Fe³⁺), or an alkali metal cation                    such as Na⁺ or K⁺, or an alkaline-earth metal cation                    such as Mg²⁺ or Ca²⁺, or an ammonium cation;                -   iii) a saturated or unsaturated (C₁-C₆)alkoxy                    radical;                -   iv) a radical —NR_(f)R_(g) with R_(f) and R_(g),                    which may be identical or different, representing a                    hydrogen atom or a (C₁-C₆)alkyl group.

Furthermore preferably, R′₆ represents a hydroxyl radical, an alkoxide—O⁻, M⁺, a saturated (C₁-C₆)alkoxy radical, in particular methoxy orethoxy, or an amino radical NH₂;

-   -   or else R′₁ and R′₂ form, with the nitrogen atom to which they        are attached, an optionally substituted heterocycloalkyl, such        as piperazino, piperidino or morpholino.    -   R″ is as previously defined, and preferably represents a        hydrogen atom or an acetyl radical, and preferably a hydrogen        atom;    -   R′″ represents a hydrogen atom, or a (C₁-C₆)alkyl group, or a        —CH₂—OR″ group with R″ as defined previously, in particular        hydrogen or an acetyl radical, and preferably a hydrogen atom.        Preferably, R′″ represents a hydrogen atom, or a (C₁-C₄)alkyl        group such as methyl, or a —CH₂—OR″ group with R″ denoting a        hydrogen atom or an acetyl radical.

According to one particular embodiment, the compounds of the inventionare of formula (I′). By way of example of compounds of formula (I′),mention may be made of the compounds 2, 3 and 4 previously described,and also the salts, solvates and isomers thereof.

According to another particular embodiment of the invention, thecompounds of the invention are of formula (I″).

According to another particular embodiment of the invention, thecompounds of the invention are of formula (I″″).

According to another particular embodiment of the invention, thecompounds of the invention are of formula (I′a). According to anotherparticular embodiment of the invention, the compounds of the inventionare of formula (I″a). According to another particular embodiment of theinvention, the compounds of the invention are of formula (I″″a).

According to another particular embodiment of the invention, thecompounds of the invention are of formula (I′b). By way of example of acompound of formula (I′b), mention may be made of the compound 5previously described, and also the salts, solvates and isomers thereof.

According to one particular embodiment, S* and S*′ represent amonosaccharide chosen from glucose, galactose, mannose, xylose, lyxose,fucose, arabinose, rhamnose, ribose, deoxyribose, quinovose, fructose,sorbose, talose, threose, erythrose, N-acetylglucosamine,N-acetylgalactosamine, glucosamine and galactosamine.

In particular, S* and S*′ represent a monosaccharide chosen fromD-glucose, D-galactose, D-mannose, D-xylose, L-xylose, D-lyxose,L-lyxose, L-fucose, L-arabinose, D-arabinose, L-rhamnose, L-ribose,D-ribose, 2-deoxy-D-ribose, 2-deoxy-L-ribose, D-quinovose, D-fructose,L-sorbose, D-talose, D-threose, D-erythrose, L-threose, L-erythrose,N-acetyl-D-glucosamine, N-acetyl-D-galactosamine, D-glucosamine andD-galactosamine. Preferably, S denotes a monosaccharide chosen fromD-glucose, D-galactose, D-mannose, D-xylose, D-lyxose, L-fucose,L-arabinose, L-rhamnose, D-ribose, 2-deoxy-D-ribose, D-quinovose,D-fructose, L-sorbose, D-talose, D-threose, D-erythrose,N-acetyl-D-glucosamine, N-acetyl-D-galactosamine, D-glucosamine andD-galactosamine.

Advantageously, S* and S*′ represent a monosaccharide chosen fromglucose, xylose, rhamnose, mannose and galactose or a disaccharidechosen from lactose, maltose and cellobiose. In particular, S* denotes amonosaccharide chosen from D-glucose, D-xylose, L-rhamnose, D-mannoseand D-galactose or a disaccharide chosen from D-lactose, D-maltose andD-cellobiose.

Preferably, S* and S*′ represent a sugar chosen from glucose, xylose,rhamnose and lactose. More particularly, S* and S*′ denote a sugarchosen from D-glucose, D-xylose, L-rhamnose and D-lactose.Preferentially, S* and S*′ denote glucose, rhamnose or xylose. Inparticular, S* and S*′ denote D-glucose, L-rhamnose or D-xylose.

According to another particular embodiment, S* and S*″ represent apolysaccharide and in particular a disaccharide chosen from lactose,maltulose, palatinose, lactulose, amygdalose, turanose, cellobiose,isomaltose, rutinose and maltose.

According to one particular embodiment, the radicals S* and S*″represent a polysaccharide and in particular a disaccharide chosen fromD-lactose, maltulose, palatinose, lactulose, amygdalose, D-turanose,D-cellobiose, isomaltose, rutinose and D-maltose.

According to another particular embodiment, R represents an amino group—NR′R′₂ with R′₁ and R′₂, independently of one another, representing:

-   -   for R′₁: a hydrogen atom or a (C₁-C₁₈)alkyl, preferably        (C₁-C₆)alkyl, group, preferentially a methyl;    -   for R′₂: a radical such as:

in which:

-   -   j=0 or 1; preferably j=0;    -   R′₄ represents a hydrogen atom when j=1, and in the other cases        (that is to say when j=0) R′₄ is chosen from the radicals        described below:

-   -   R′₄ can also form, with R′₁ and the nitrogen which bears R′₁, an        alipsaturated heterocycle of formula A1 or A2 or A3:

-   -   R′₆ denotes        -   i) a hydroxyl radical —OH;        -   ii) an alkoxide —O⁻, M⁺ with M⁺ representing a cation such            as zinc (Zn²⁺), manganese (Mn²⁺), copper (Cu²⁺), iron (Fe²⁺,            Fe³⁺), or an alkali metal cation such as Na⁺ or K⁺, or an            alkaline-earth metal cation such as Mg²⁺ or Ca²⁺, or an            ammonium cation;        -   iii) a saturated (C₁-C₆)alkoxy radical, preferably methoxy            or ethoxy;        -   iv) an amino radical —NH₂.

According to another particular embodiment, R represents an amino group—NR′₁R′₂ with R′₁ and R′₂, independently of one another, representing:

-   -   for R′₁: a hydrogen atom or a (C₁-C₁₀)alkyl, preferably        (C₁-C₆)alkyl, group, preferentially a methyl;    -   for R′₂: a hydrogen atom or a (C₁-C₁₆)alkyl group,        preferentially a methyl or an n-tetradecyl;    -   R″ is as previously defined, and preferably represents a        hydrogen atom or an acetyl radical, and preferably a hydrogen        atom;    -   R′″ represents a hydrogen atom, or a (C₁-C₆)alkyl group, or a        —CH₂—OR″ group with R″ as defined previously, in particular        hydrogen or an acetyl radical, and preferably a hydrogen atom.        Preferably, R′″ represents a hydrogen atom, or a (C₁—C)alkyl        group such as methyl, or a —CH₂—OR″ group with R″ denoting a        hydrogen atom or an acetyl radical.

According to this embodiment, according to a first variant, R′₁ and R′₂are identical.

According to a second variant of this embodiment, R′₁ and R′₂ aredifferent and preferably R′₁ denotes a hydrogen atom.

According to another particular embodiment, R represents a hydroxylgroup; this hydroxyl can be in the form of an alkoxide O⁻, M⁺ with M⁺representing a cation such as zinc (Zn²⁺), manganese (Mn²⁺), copper(Cu²⁺), iron (Fe²⁺, Fe³⁺), sodium (Na⁺), potassium (K⁻), magnesium(Mg²⁺), calcium (Ca²⁺), or ammonium; (when R is in the form of analkoxide, it forms, with the carbonyl in the alpha position acarboxylate function COO⁺, M⁺ with M⁺ as previously defined);

-   -   R″ is as previously defined, and preferably represents a        hydrogen atom or an acetyl radical, and preferably a hydrogen        atom;    -   R′″ represents a hydrogen atom, or a (C₁-C₆)alkyl group, or a        —CH₂—OR″ group with R″ as defined previously, in particular        hydrogen or an acetyl radical, and preferably a hydrogen atom.        Preferably, R′″ represents a hydrogen atom, or a (C₁—C)alkyl        group such as methyl, or a —CH₂—OR″ group with R″ denoting a        hydrogen atom or an acetyl radical.

A subject of the invention is also the novel compounds of formula (IIa),and also the solvates and/or isomers and/or salts thereof for which:

with:

-   -   S*₁ denoting a monosaccharide sugar radical chosen from:        D-glucose, D-galactose, D-mannose, D-xylose, D-lyxose, L-fucose,        L-arabinose, D-arabinose, L-rhamnose, D-quinovose, D-fructose,        L-sorbose, D-talose, N-acetyl-D-glucosamine,        N-acetyl-D-galactosamine, D-glucosamine and D-galactosamine;        -   the saccharide unit comprising one or more hydroxyl groups            optionally substituted with a radical R′_(a) chosen from:        -   i) (C₁-C₆)alkyl; or        -   ii) an acetyl radical;        -   said monosaccharide radical not being able to comprise a            (hemi)acetal or (hemi)aminal function;        -   said monosaccharide radical being connected to the rest of            the molecule by a bond between the C₁ carbon atom of said            monosaccharide radical, this bond possibly being α or β            anomeric;    -   R′₃ represents a group chosen from:        i) a hydrogen atom; ii) saturated or unsaturated (C₁-C₁₈)alkyl;        iii) optionally substituted aryl such as phenyl;        iv) optionally substituted aryl(C₁-C₆)alkyl, such as benzyl;        it being understood that:    -   when S*₁ denotes a D-glucose, R′₃ cannot be a methyl or an        ethyl, and R′₃ is other than a hydrogen atom when all its        hydroxyl groups are substituted with an acetyl group        (R′_(a)=acetyl);    -   when S*₁ denotes a D-xylose, R′₃ cannot be a methyl or a        (C₁₅-C₁₈)alkyl;    -   when S*₁ denotes a D-galactose, R′₃ cannot be a hydrogen, and        R′₃ is other than a methyl or ethyl when all its hydroxyl groups        are substituted with an acetyl group (R′_(a)=acetyl);    -   when S*₁ denotes a D-mannose, R′₃ cannot be a hydrogen or a        methyl;    -   when S*₁ denotes an L-rhamnose, R′₃ is other than a hydrogen        atom or than a methyl group when all its hydroxyl groups are        substituted with an acetyl group (R′_(a)=acetyl);    -   when S*₁ denotes an L-fucose, R′₃ cannot be a hydrogen;    -   when S*₁ denotes a D-arabinose, R′₃ cannot be a methyl;    -   when S*₁ denotes a D-talose, R′₃ is other than a hydrogen atom        when all its hydroxyl groups are substituted with an acetyl        group (R′_(a)=acetyl);    -   when S*₁ denotes an N-acetyl-D-glucosamine, R′₃ cannot be an        ethyl, and R′₃ is other than a hydrogen atom when all its        hydroxyl groups are substituted with an acetyl group        (R′_(a)=acetyl);    -   the compounds of formula (IIa) have a molar mass of less than        800 Da and do not comprise more than 3 rings in total.

When R′₃ denotes a hydrogen atom, as previously mentioned, thecorresponding compounds of formula (IIa) may be in the form of salts(carboxylates COO⁺, M⁺, with M⁺ having the definition previouslymentioned).

Preferably, S*₁ denotes a sugar chosen from D-glucose or D-xylose, morepreferentially D-glucose.

Preferably, the hydroxyl groups of S*₁ are not substituted.

Preferably, R′₃ represents a hydrogen atom or a (C₁-C₁₈)alkyl group,which is preferably saturated, and more preferentially a C₂-C₆ alkylgroup, in particular ethyl.

Among the compounds of formula (IIa), mention may in particular be madeof the compound 2 (and/or solvates thereof and/or salts thereof):

A subject of the invention is also the novel compounds of formula (IIb),and also the solvates and/or isomers and/or salts thereof:

with:

-   -   S*₂ denoting a monosaccharide sugar radical or denotes a        polysaccharide sugar radical comprising 2 saccharide units, each        saccharide unit (the saccharide unit in the case of a        monosaccharide or each saccharide unit in the case of        polysaccharides) comprising one or more hydroxyl groups        optionally substituted with a radical R′_(b) chosen from:        -   i) (C₁-C₆)alkyl; or        -   ii) an acetyl radical;        -   said monosaccharide or polysaccharide radical not being able            to comprise a (hemi)acetal or (hemi)aminal function;        -   said monosaccharide or polysaccharide radical possibly also            comprising one or more amino groups NR_(b)R_(c) with R_(b)            and R_(c), which may be identical or different, representing            a hydrogen atom, or an acetyl group, or a protective group            for the amino function, such as (C₂-C₆)alkyl(thio)carbonyl;        -   said monosaccharide or polysaccharide radical being            connected to the rest of the molecule by a bond between the            C₁ carbon atom of one of the sugars of said monosaccharide            or polysaccharide radical, this bond possibly being α or β            anomeric;    -   R″₃ represents a group chosen from:        i) a hydrogen atom; ii) saturated or unsaturated (C₂-C₁₄)alkyl;        it being understood that:    -   when S*₂ denotes a monosaccharide, R″₃ cannot be a hydrogen or        an ethyl;    -   when S*₂ denotes a monosaccharide in the pyranose form, R″₃        cannot be an n-butyl;    -   the compounds of formula (IIb) have a molar mass of less than        800 Da and do not comprise more than 3 rings in total.

When R′₃ denotes a hydrogen atom, as previously mentioned, thecorresponding compounds of formula (IIb) may be in the form of salts(carboxylates COO⁺, M⁺, with M⁺ having the definition previouslymentioned).

According to a particular form of the invention, S*2 denotes amonosaccharide as defined previously with the exception of D-glucose,D-galactose, D-mannose, D-xylose, D-lyxose, L-fucose, L-arabinose,D-arabinose, L-rhamnose, D-quinovose, D-fructose, L-sorbose, D-talose,N-acetyl-D-glucosamine, N-acetyl-D-galactosamine, D-glucosamine andD-galactosamine.

When S*₂ denotes a disaccharide, it is preferably from the followingdisaccharides: lactose, maltulose, palatinose, lactulose, amygdalose,turanose, cellobiose, isomaltose, rutinose and maltose. Morepreferentially, it is D-lactose, D-maltose or D-cellobiose.

Preferably, the hydroxyl groups of S*₂ are not substituted.

Preferably, R″₃ represents a hydrogen atom or a (C₂-C₆)alkyl group,which is preferably saturated, in particular ethyl.

A subject of the invention is also the novel compounds of formula (IIc),and also the solvates and/or isomers and/or salts thereof:

in which S*, R₁, R₀ and w are as previously defined.

-   -   S* denotes a monosaccharide sugar radical or denotes a        polysaccharide sugar radical comprising from 2 to 5 saccharide        units, preferably from 2 to 3 saccharide units, each saccharide        unit (the saccharide unit in the case of a monosaccharide or        each saccharide unit in the case of polysaccharides) comprising        one or more hydroxyl groups optionally substituted with a        radical R′ chosen from:        -   i) (C₁-C₆)alkyl; or        -   ii) an acetyl radical;        -   said monosaccharide or polysaccharide radical not being able            to comprise a (hemi)acetal or (hemi)aminal function;        -   said monosaccharide or polysaccharide radical possibly also            comprising one or more amino groups NR_(b)R_(c) with R_(b)            and R_(c), which may be identical or different, representing            a hydrogen atom, or an acetyl group, or a protective group            for the amino function, such as (C₂-C₆)alkyl(thio)carbonyl;        -   said monosaccharide or polysaccharide radical being            connected to the rest of the molecule by a bond between the            C₁ carbon atom of one of the sugars of said monosaccharide            or polysaccharide radical, this bond possibly being α or β            anomeric;            -   R_(l) and R_(o), independently of one another, denote a                hydrogen atom or a methyl radical, it being understood                that R_(l) and R_(o) cannot simultaneously denote a                methyl radical;            -   w=1 to 10, limits included,                it being understood that:                the compounds of formula (IIc) have a molar mass of less                than 800 Da and do not comprise more than 3 rings in                total.

Preferably, the hydroxyl groups of S* are not substituted and theoptional amino groups are free (—NH₂) or all substituted with an acetylgroup (—CO—CH₃) (R_(b)═H and R_(c)═H or acetyl).

Preferably, w is between 1 and 5, more preferentially between 1 and 3.

A subject of the invention is also the novel compounds of formula(IIIa), and also the solvates and/or isomers and/or salts thereof forwhich:

with:

-   -   S*₃ denoting a monosaccharide sugar radical chosen from:        D-xylose, D-fructose, L-sorbose, N-acetyl-D-glucosamine,        N-acetyl-D-galactosamine, D-glucosamine, D-galactosamine and in        particular D-xylose;        -   the saccharide unit comprising one or more hydroxyl groups            optionally substituted with a radical R′_(c) chosen from:        -   i) (C₁-C₆)alkyl; or        -   ii) an acetyl radical;        -   said monosaccharide radical not being able to comprise a            (hemi)acetal or (hemi)aminal function;        -   said monosaccharide radical being connected to the rest of            the molecule by a bond between the C₁ carbon atom of said            monosaccharide radical, this bond possibly being α or β            anomeric;    -   R″₁ represents a group chosen from:        -   i) a hydrogen atom;        -   ii) a (C₁-C₁₈)alkyl group;        -   iii) a (C₂-C₁₈)alkenyl group;    -   R″₂ represents a group chosen from:        -   i) a hydrogen atom;        -   ii) a (C₁-C₁₈)alkyl group;        -   iii) a (C₂-C₁₈)alkenyl group;        -   iv) an aryl(C₁-C₄)alkyl group optionally substituted in            particular with at least one hydroxyl and/or saturated or            unsaturated (C₁-C₄)alkoxy group;        -   v) an optionally substituted aryl or heteroaryl radical;            or else R″₁ and R″₂ form, with the nitrogen atom to which            they are attached, an optionally substituted            heterocycloalkyl, such as piperazino, piperidino or            morpholino,            it being understood that:            the compounds of formula (IIIa) have a molar mass of less            than 800 Da and do not comprise more than 3 rings in total.

Preferably, S*₃ denotes D-xylose.

Preferably, the hydroxyl groups of S*₃ are not substituted.

Preferably, R″₁ denotes a hydrogen atom or a C₁-C₄ alkyl group, such asin particular a methyl group. Preferentially, R″₂ denotes a hydrogenatom or a C₁-C₁₆ alkyl group such as in particular a methyl orn-tetradecyl group.

Among the compounds of formula (IIIa), the novel compounds 3 and 5(and/or solvates thereof and/or salts thereof) is more particularlypreferred:

A subject of the invention is also the novel compounds of formula(IIIb), and also the solvates and/or isomers and/or salts thereof forwhich:

with:

-   -   S*₄ denoting a monosaccharide sugar radical or denotes a        polysaccharide sugar radical comprising from 2 to 5 saccharide        units, preferably from 2 to 3 saccharide units, each saccharide        unit (the saccharide unit in the case of a monosaccharide or        each saccharide unit in the case of polysaccharides) comprising        one or more hydroxyl groups optionally substituted with a        radical R′_(d) chosen from:        -   i) (C₁-C₆)alkyl; or        -   ii) an acetyl radical;        -   said monosaccharide or polysaccharide radical not being able            to comprise a (hemi)acetal or (hemi)aminal function;        -   said monosaccharide or polysaccharide radical possibly also            comprising one or more amino groups NR_(b)R_(c) with R_(b)            and R_(c), which may be identical or different, representing            a hydrogen atom, or an acetyl group, or a protective group            for the amino function, such as (C₂-C₆)alkyl(thio)carbonyl;            with the exclusion of the monosaccharides of 5-aminofuranose            type;        -   said monosaccharide or polysaccharide radical being            connected to the rest of the molecule by a bond between the            C₁ carbon atom of one of the sugars of said monosaccharide            radical, this bond possibly being α or β anomeric;    -   R′″₁ represents a group chosen from:        -   i) a hydrogen atom;        -   ii) a (C₁-C₁₈)alkyl group;        -   iii) a (C₂-C₁₈)alkenyl group;    -   R′″₂ represents a group chosen from:        -   i) a (C₁-C₁₈)alkyl group; or        -   ii) a (C₂-C₁₈)alkenyl group;        -   iii) an aryl(C₁-C₄)alkyl group optionally substituted in            particular with at least one hydroxyl and/or saturated or            unsaturated (C₁-C₄)alkoxy group;        -   iv) an optionally substituted aryl or heteroaryl radical;            or else R′″₁ and R′″₂ form, with the nitrogen atom to which            they are attached, an optionally substituted            heterocycloalkyl, such as piperazino or morpholino; the            piperidine ring is excluded;            it being understood that, in the case where R′″₁ represents            a hydrogen atom:    -   when S*₄ denotes a D-galactose, R′″₂ cannot be an alkyl or        alkenyl group;    -   when S*₄ denotes a monosaccharide, R′″₂ cannot be a substituted        or unsubstituted benzyl group;    -   when S*₄ denotes a monosaccharide of pyranose type, R′″₂ cannot        be a substituted or unsubstituted phenyl group or a        2-benzothiazolyl group or a 2-benzimidazolyl group;        it being understood that:        the compounds of formula (IIIb) have a molar mass of less than        800 Da and do not comprise more than 3 rings in total;        and that the following compound is excluded:

When S*₄ denotes a monosaccharide, said monosaccharide is other thanD-xylose, D-fructose, L-sorbose, N-acetyl-D-glucosamine,N-acetyl-D-galactosamine, D-glucosamine, D-galactosamine.

When S*₄ denotes a disaccharide, it is preferably from the followingdisaccharides: lactose, maltulose, palatinose, lactulose, amygdalose,turanose, cellobiose, isomaltose, rutinose and maltose. Morepreferentially, it is D-lactose, D-maltose or D-cellobiose.

Preferably, the hydroxyl groups of S*₄ are not substituted.

Preferably, R′″₁ denotes a hydrogen atom or a C₁-C₄ alkyl group, such asin particular a methyl radical. Preferentially, R′″₁ denotes a methylgroup. Preferably, R′″₂ denotes a hydrogen atom or a C₁-C₄ alkyl groupsuch as in particular a methyl radical.

Among the compounds of formula (IIIb), mention may in particular be madeof the novel compound 4 (and/or solvates thereof and/or salts thereof):

A subject of the invention is also the novel compounds of formula(IIIc), and also the solvates and/or isomers and/or salts thereof forwhich:

with:

-   -   S*₃ denoting a monosaccharide sugar radical chosen from:        D-xylose, D-fructose, L-sorbose, N-acetyl-D-glucosamine,        N-acetyl-D-galactosamine, D-glucosamine and D-galactosamine;        -   the saccharide unit comprising one or more hydroxyl groups            optionally substituted with a radical R′_(c) chosen from:        -   i) (C₁-C₆)alkyl; or        -   ii) an acetyl radical;        -   said monosaccharide radical not being able to comprise a            (hemi)acetal or (hemi)aminal function;        -   said monosaccharide radical being connected to the rest of            the molecule by a bond between the C₁ carbon atom of one of            the sugars of said monosaccharide radical, this bond            possibly being α or β anomeric;    -   R″₁ represents a group chosen from:        -   i) a hydrogen atom;        -   ii) a (C₁-C₁₈)alkyl group;        -   iii) a (C₂-C₁₈)alkenyl group;    -   i=0 or 1;    -   R₄ represents a hydrogen atom or R₄ is chosen from the radicals        (a1) to (a32) described below:

R₄ can also form, with R″₁ and the nitrogen atom which bears R″₁, asaturated heterocycle of formula A or A2 or A3:

-   -   R₆ denotes        -   i) a hydroxyl radical —OH;        -   ii) an alkoxide —O⁻, M⁺ with M⁺ representing a cation such            as zinc (Zn²⁺), manganese (Mn²⁺), copper (Cu²⁺), iron (Fe²⁺,            Fe³⁺), or an alkali metal cation such as Na⁺ or K⁺, or an            alkaline-earth metal cation such as M²⁺ or Ca²⁺, or an            ammonium cation;        -   iii) a saturated or unsaturated (C₁-C₆)alkoxy radical;        -   iv) a radical —NR_(f)R_(g) with R_(f) and R_(g), which may            be identical or different, representing a hydrogen atom or a            (C₁-C₆)alkyl group.

It being understood that

the compounds of formula (IIIc) have a molar mass of less than 800 Daand do not comprise more than 3 rings in total.

Preferably, the hydroxyl groups of S*₃ are not substituted.

Preferably, R″₁ denotes a hydrogen atom or a C₁-C₄ alkyl group, such asin particular a methyl radical. Preferentially, R″₁ denotes a hydrogenatom.

Preferably, R₆ denotes a hydroxyl, ethoxy or NH₂ group.

When R₆ denotes a hydrogen atom, the corresponding compounds of formula(IIIc) can of course be in the form of salts (carboxylate).

Preferably, i=0 and R₄ represents a hydrogen atom or a radical chosenfrom the radicals (a1) or (a5) or (a16) below:

A subject of the invention is also the novel compounds of formula(IIId), and also the solvates and/or isomers and/or salts thereof:

with:

-   -   S* denoting a monosaccharide sugar radical or denotes a        polysaccharide sugar radical comprising from 2 to 5 saccharide        units, preferably from 2 to 3 saccharide units, each saccharide        unit (the saccharide unit in the case of a monosaccharide or        each saccharide unit in the case of polysaccharides) comprising        one or more hydroxyl groups optionally substituted with a        radical R′ chosen from:        -   i) (C₁-C₆)alkyl; or        -   ii) an acetyl radical;        -   said monosaccharide or polysaccharide radical not being able            to comprise a (hemi)acetal or (hemi)aminal function;        -   said monosaccharide or polysaccharide radical possibly also            comprising one or more amino groups NR_(b)R_(c) with R_(b)            and R_(c), which may be identical or different, representing            a hydrogen atom, or an acetyl group, or a protective group            for the amino function, such as (C₂-C₆)alkyl(thio)carbonyl;        -   said monosaccharide or polysaccharide radical being            connected to the rest of the molecule by a bond between the            C₁ carbon atom of one of the sugars of said monosaccharide            or polysaccharide radical, this bond possibly being α or β            anomeric;    -   R″₁ represents a group chosen from:        -   i) a hydrogen atom;        -   ii) a (C₁-C₁₈)alkyl group;        -   iii) a (C₂-C₁₈)alkenyl group;    -   i=0 or 1;    -   R₄ represents a hydrogen atom or R₄ is chosen from the radicals        (a1) to (a32) described below:

R₄ can also form, with R″₁ and the nitrogen atom which bears R″₁, asaturated heterocycle of formula A1 or A2 or A3:

R₆ denotes

-   -   i) a hydroxyl radical —OH;    -   ii) an alkoxide —O⁻, M⁺ with M⁺ representing a cation such as        zinc (Zn²⁺), manganese (Mn²⁺), copper (Cu²⁺), iron (Fe²⁺, Fe³⁺),        or an alkali metal cation such as Na⁺ or K⁺, or an        alkaline-earth metal cation such as Mg²⁺ or Ca²⁺, or an ammonium        cation;    -   iii) a saturated or unsaturated (C₁-C₆)alkoxy radical;    -   iv) a radical —NR_(f)R_(g) with R_(f) and R_(g), which may be        identical or different, representing a hydrogen atom or a        (C₁-C₆)alkyl group.

It being understood that: in the case where R″₁ represents a hydrogenatom and when S* denotes a monosaccharide of pyranose type, R₆ cannot bea methyl or a hydroxyl group;

it being understood that:the compounds of formula (IIId) have a molar mass of less than 800 Daand do not comprise more than 3 rings in total;and that the following compound is excluded:

Preferably, the hydroxyl groups of S* are not substituted.

Preferably, R″₁ denotes a hydrogen atom or a C₁-C₄ alkyl group, such asin particular a methyl radical. Preferentially, R″₁ denotes a hydrogenatom.

Preferably, R₆ denotes a hydroxyl, ethoxy or NH₂ group.

When R″₆ denotes a hydroxyl group, the corresponding compounds offormula (IIId) can of course be in the form of salts (carboxylates).

Preferably, i=0 and R₄ represents a hydrogen atom or a radical chosenfrom the radicals (a1) or (a5) or (a16) below:

A subject of the invention is also the novel compounds of formula(IIIe), and also the solvates and/or isomers and/or salts thereof forwhich:

-   -   S* denotes a monosaccharide sugar radical or denotes a        polysaccharide sugar radical comprising from 2 to 5 saccharide        units, preferably from 2 to 3 saccharide units, each saccharide        unit (the saccharide unit in the case of a monosaccharide or        each saccharide unit in the case of polysaccharides) comprising        one or more hydroxyl groups optionally substituted with a        radical R′ chosen from:        -   i) (C₁-C₆)alkyl; or        -   ii) an acetyl radical;        -   said monosaccharide or polysaccharide radical not being able            to comprise a (hemi)acetal or (hemi)aminal function;        -   said monosaccharide or polysaccharide radical possibly also            comprising one or more amino groups NR_(b)R_(c) with R_(b)            and R_(c), which may be identical or different, representing            a hydrogen atom, or an acetyl group, or a protective group            for the amino function, such as (C₂-C₆)alkyl(thio)carbonyl;        -   said monosaccharide or polysaccharide radical being            connected to the rest of the molecule by a bond between the            C₁ carbon atom of one of the sugars of said monosaccharide            or polysaccharide radical, this bond possibly being α or β            anomeric;    -   R″₁ represents a group chosen from:        -   i) a hydrogen atom;        -   ii) a (C₁-C₁₈)alkyl group;        -   iii) a (C₂-C₁₈)alkenyl group;    -   R_(h) and R_(k), independently of one another, denote a hydrogen        atom or a methyl radical, it being understood that R_(h) and        R_(k) cannot simultaneously denote a methyl radical;    -   y=1 to 10, limits included;        it being understood that        the compounds of formula (IIIe) have a molar mass of less than        800 Da and do not comprise more than 3 rings in total.

Preferably, the hydroxyl groups of S* are not substituted and theoptional amino groups are free (—NH₂) or substituted with an acetylgroup (—CO—CH₃) (R_(b)═H and R_(c)═H or acetyl).

Preferably, y is between 1 and 5, more preferentially between 1 and 3.

The preferred novel compounds are the compounds 1 to 5 previouslydescribed.

Process for Preparing the Compounds of Formula (I), in Particular theCompounds of Formulae (IIa), (IIb), (IIc), (IIIa), (IIIb), (IIIc),(IIId) and/or (IIIe), of the Invention

Another subject of the invention is the process for preparing, or aprocess for the chemical synthesis of, the compounds of formula (I) aspreviously defined for which A is other than a hydrogen atom, on the onehand, and of the compounds of formula (I) for which A denotes a hydrogenatom and the sugar S* is a monosaccharide in pyranose or furanose form,on the other hand, according to scheme (1) described below.

The compounds of formula (II¹) comprise certain compounds (carboxylicacids) of formulae (IIa) and (IIb). The compounds of formula (II²)comprise certain compounds (esters) of formulae (IIa) and (IIb), andalso the compounds of formula (IIc).

The compounds of formula (III¹) comprise the compounds of formulae(IIIa), (IIIb), (IIIc), (IIId) and (IIIe).

The novel compounds of formulae (II¹), (II²) and (III¹) can be preparedaccording to the following scheme (1):

According to this scheme, if, in compound (IV), A denotes a hydrogenatom, the synthetic step 1a must be preceded by a step of protecting theradicals AO═OH of the sugar. In this case, compounds (II¹), (II²) andalso compounds (III¹) obtained via (II¹) are obtained in the form ofprotected sugars (A other than H) and the corresponding compounds (II¹),(II²), (III¹) for which A=H are obtained after a deprotection step.

The compounds (III¹) may also be obtained by reaction of a protected orunprotected compound (IV) (A=H or other than H) with a beta-keto amide(VII) according to step 1b. If (IV) is such that A=H, then, in thiscase, (III¹) is such that A=H. If (IV) is such that A is other than H,then (III¹) is such that A is other than H and compound (III¹) for whichA=H is obtained after a step of deprotection of the hydroxyls of thesugar.

The synthetic route described in scheme (1) comprises the followingsteps:

-   -   Step 1a consists in reacting a monosaccharide or a        polysaccharide of formula (IV) with Meldrum's acid (V), in        particular in the presence of an organic base such as a tertiary        amine, for instance triethylamine or diisopropylethylamine.

In which formula (IV), A, R_(a), R_(b), R_(c), R_(e), n, and m are aspreviously defined, p′ and q′ representing an integer inclusivelybetween 0 and 4, with p′+q′ inclusively between 0 and 4, in particularbetween 0 and 2, preferably p′+q′=0 or 1, it being understood that thetwo units between square brackets can be reversed; the compound offormula (IV) being represented in the scheme by:

step 1 being carried out in particular in a non-protic polar solventsuch as DMF or acetonitrile, by heating optionally at a temperaturebetween 30° C. and 100° C., in particular at 40-50° C., preferably for aperiod of between 1 h and 7 days, in particular between 2 and 7 days,such as 2 days, so as to give the compound comprising sugar unit (VI).

-   -   Step 2 consists in carrying out a hydrolysis of the compound        (VI), in particular in acid medium, and in particular in the        presence of a weak organic acid such as acetic acid, which can        also serve as solvent, or else in acid medium diluted in aqueous        solution, such as hydrochloric acid, in a protic polar solvent        such as water, by optionally heating at a temperature of between        30° C. and 120° C., in particular between 80° C. and 100° C.,        such as 100° C., for a period of between 2 h and 24 h, in        particular between 2 h and 5 h, so as to give an acid        C-glycoside compound (II¹).    -   Step 3 consists in reacting the acid (II¹) either with an        alcohol R_(r)—OH so as to give the ester compounds of formula        (II²) by esterification, or with an amine R_(r1)R_(r2)NH so as        to give the amide compounds of formula (III¹) by        N-acylation/amidation.

The first 2 steps are in particular described by Mata et al., Carbohydr.Res. 1990, 201, 223-31; Mata et al., Carbohydr. Res. 1992, 225, 159-61;Köll et al., J. Carbohydr. Chem. 2000, 19, 1019-47.

Alternatively, in certain cases, (in particular when R_(r1) and R_(r2)are alkyl groups), it may be possible to obtain amide compounds offormula (III¹) directly by means of a Lubineau reaction (step 1 b)between the monosaccharide or the polysaccharide of formula (IV) and anacetoacetamide compound of formula (VII). The reaction takes place inparticular in the presence of a mineral base such as M⁺OH⁻, M⁺representing a cation, such as NaOH, or preferably of a weak base suchas (bi)carbonate, in particular with an alkali metal (bi)carbonate, orin the presence of an organic base such as triethylamine ordiisopropylethylamine, in particular in a polar protic solvent such aswater, optionally by heating at a temperature between 30° C. and 100°C., in particular at between 50° C. and 60° C., preferably for a periodof between 1 hour and 24 hours, in particular between 2 hours and 5hours, such as 2 or 3 hours.

The compounds of formula (I) for which A denotes a hydrogen atom and thesugar is in furanose form may also be obtained according to scheme (2)below:

This alternative synthetic route comprises the following steps:

-   -   step 1 consists in reacting a monosaccharide or a polysaccharide        of formula (IV) with Meldrum's acid (V), in particular in the        presence of an organic base such as a tertiary amine, for        instance triethylamine or tert-butylamine. Step 1 is performed        in particular in a polar aprotic solvent such as DMF or        acetonitrile, optionally heating to a temperature of between        30° C. and 100° C., in particular 45-49° C., preferably for a        time of between 1 hour and 7 days, in particular between 2 and 7        days, such as 5 days, such as 5 days, to give a lactone        intermediate fused with a sugar unit in furanose form (VIII);    -   step 2a consists in performing a hydrolysis of compound (VIII),        especially in acidic medium, and in particular in dilute acidic        medium as an aqueous solution such as hydrochloric acid, in a        polar protic solvent such as water, optionally heating to a        temperature of between 30° C. and 120° C., in particular between        80° C. and 100° C., such as 100° C., for a time of between 2        hours and 24 hours, to give a C-glycoside acid compound (II¹) in        furanose form;

Alternatively, step 2 may also consist in opening the lactone (VIII) inaqueous basic medium, especially in the presence of a strong inorganicbase such as sodium hydroxide or potassium hydroxide, in a polar proticsolvent such as water, at room temperature or with heating optionally toa temperature of between 30° C. and 120° C., in particular between 80°C. and 100° C., such as 100° C., for a time of between 2 hours and 24hours, to give a C-glycoside acid compound (II¹) in furanose form;

-   -   step 2b consists in performing opening of the lactone        compound (VIII) with an alcohol R_(r)—OH, especially in acidic        medium, such as in the presence of hydrochloric acid, in a polar        aprotic solvent such as THF, dioxane or DMF (the alcohol        R_(r)—OH may itself be used as solvent), optionally heating to a        temperature of between 30° C. and 160° C., in particular between        80° C. and 120° C., such as 100° C., for a time of between 2        hours and 24 hours, to give a C-glycoside ester compound (II²)        in furanose form. Alternatively, the lactone (VIII) may be        opened with the alcohol R_(r)—OH deprotonated beforehand with a        strong base such as Na or NaH to form the corresponding        alkoxide;    -   step 2c consists in performing opening of the lactone        compound (VIII) with an amine R_(r1)R_(r2)NH, in a polar aprotic        solvent such as THF, dioxane or DMF (the amine R_(r1)R_(r2)NH        may itself be used as solvent), optionally heating to a        temperature of between 30° C. and 160° C., in particular between        80° C. and 120° C., such as 100° C., for a time of between 2        hours and 24 hours, to give a C-glycoside amide compound (III¹)        in furanose form.

All the reagents are obtained by conventional methods known by thoseskilled in the art. The latter will take care to protect or deprotectaccording to the synthesis steps. It may be necessary to carry out astep of protecting the hydroxyl groups (groups A) and/or the aminogroups (group NR_(b)R_(c)) of the sugar unit (IV), before the firststep, and then to carry out the optional deprotection thereof after thethird step. For example:

The compounds can be obtained from a sugar (IV) comprising OH group(s)which are free or substituted with a C₁-C₆ alkyl group or with a C₁-C₆alkylcarbonyl group, or comprising an OH group protected by a protectivegroup, said protective group being accessible according to the methodsdescribed by Peter G. M. Wuts and Theodora W. Greene, in Greene'sProtective Groups in Organic Synthesis, Fourth Edition, Wiley, 2006;processes for alkylation or acylation of the hydroxyls of sugars areknown and in particular described in Durantie, Estelle et al,Chemistry—A European Journal, 18(26), 8208-8215 (2012).

The sugar (IV) can also contain one or more amino group(s) substitutedwith the same C₁-C₆ alkylcarbonyl group, or with a PG such as thosedescribed by Peter G. M. Wuts and Theodora W. Greene, in Greene'sProtective Groups in Organic Synthesis, Fourth Edition, Wiley, 2006. Theprocesses for alkylation, or acylation of the hydroxyls of sugars areknown by those skilled in the art and are in particular described in:Durantie, Estelle et al, Chemistry—A European Journal, 18(26), 8208-8215(2012).

The step of alkylation of the hydroxyl group is generally carried out bytreatment with a base, often a relatively strong base, of NaH, tBuOK ortBuONa type, in the presence of an alkylation agent such as an alkylhalide, in a non-protic polar solvent such as DMF, NMP, THF, ACN oracetone.

The N-acylation methods are also well known by those skilled in the artand consist in reacting the amine with either a reactive derivative of acarboxylic acid, such as an acid anhydride or an acid halide (acidchloride), or a carboxylic acid activated in situ via a coupling agentsuch as HOBt, EDCl, CDI, DCC, HATU or PyBOP, in the optional presence ofan organic base such as DIEA or TEA, or of a mineral base such as NaOH,and optionally of DMAP in an equimolar or catalytic amount, in anon-protic polar solvent such as DCM, THF, DMF or ACN, or optionally aprotic solvent such as water.

The esterification methods are generally carried out by treatment withalcohol, either a reactive derivative of a carboxylic acid, such as anacid anhydride or an acid halide (acid chloride), or a carboxylic acidactivated in situ via a coupling agent such as HOBt, EDCl, CDI or DCC,optionally in the presence of a base such as pyridine, triethylamine ordiisopropylethylamine, sodium acetate or sodium hydroxide, andoptionally of DMAP in an equimolar or catalytic amount, in a non-proticpolar solvent such as ACN, pyridine, DCM, THF or acetone, or optionallya protic solvent such as water. Alternatively, the hydroxyl can betreated with a carboxylic acid in an acid medium (APTS, anhydrous HCl,H₂SO₄), with a device for eliminating the water formed, such as thepresence of a desiccant, for instance silica gel, Na₂SO₄, MgSO₄ or P₂O₅,or a Dean Stark apparatus using a volatile solvent which forms anazeotrope with water, for instance toluene or cyclohexane.

The present invention also relates to a composition comprising, in aphysiologically acceptable medium, at least one compound of formula (I),and in particular at least one compound of formula (IIa), (IIb), (IIc),(IIIa), (IIIb), (IIIc), (IIId) and/or (IIIe) and more particularly atleast one compound chosen from the compounds 2, 3, 4 and 5, as describedabove. The composition is in particular a cosmetic composition.

According to one advantageous form of the invention, the cosmeticcomposition contains at least one compound of formula (I), and inparticular at least one compound of formula (IIa), (IIIb), (IIc),(IIIa), (IIIb), (IIIc), (IIId) and/or (IIIe), and more particularly atleast one compound chosen from the compounds 2, 3, 4 and 5, aspreviously defined, and at least one additive chosen from a fragrance, athickener, a surfactant, a pigment, a dye and a preservative.

More particularly, the cosmetic composition according to the inventioncontains at least one compound chosen from the compounds 1 to 5,preferentially chosen from compounds 2, 3, 4 and 5 previously defined,and also the solvates thereof such as hydrates, and the organic ormineral acid or base salts thereof.

The compound of formula (I), and in particular the compounds of formula(IIa), (IIb), (IIc), (IIIa), (IIIb), (IIIc), (IIId) and/or (IIIe)defined above, (each compound of formula (I) if the compositioncomprises several thereof) can be present in the composition in anamount which can be between 0.01% and 20% by weight, preferably between0.1% and 15% by weight, in particular between 0.5% and 10% by weight,relative to the total weight of the composition.

The composition also comprises a physiologically acceptable medium,which is preferably a cosmetically or pharmaceutically acceptablemedium, in particular a dermatologically acceptable medium, i.e. amedium that has no unpleasant odour, colour or appearance, and that doesnot cause the user any unacceptable stinging, tautness or redness. Inparticular, the composition is suitable for topical application to theskin and skin integuments.

The term “physiologically acceptable medium” is intended to mean amedium that is compatible with human skin and skin integuments.

The composition according to the invention may then comprise waterand/or any adjuvant commonly used in the envisaged application field.

Mention may be made in particular of: organic solvents, in particularC₁-C₆ alcohols and C₂-C₁₀ carboxylic acid esters; carbon-based and/orsilicone oils, of mineral, animal and/or plant origin; water, waxes,pigments, fillers, colorants, surfactants, emulsifiers, coemulsifiers;cosmetic or dermatological active agents, UV-screening agents, polymers,hydrophilic or lipophilic gelling agents, thickeners, preservatives,fragrances, bactericides, odour absorbers and antioxidants.

These optional adjuvants may be present in the composition in aproportion of from 0.001% to 80% by weight and in particular from 0.1%to 40% by weight relative to the total weight of the composition.

The composition according to the invention may constitute a makeupcomposition, or preferably a skincare composition, and in particular acleansing, protecting, treating or care cream for the face, the hands,the feet, the major anatomical folds or the body (for example daycreams, night creams, makeup-removing creams, foundation creams oranti-sun creams); a fluid foundation, a makeup-removing milk, aprotective or care body milk or an anti-sun milk; a skincare lotion, gelor mousse, such as a cleansing lotion, or a hair composition.

A subject of the invention is also a process for cosmetic treatment ofkeratin materials such as the skin, comprising the application, to thesesaid materials such as the skin, of a composition comprising at leastone compound of formula (I), and in particular the compounds of formulae(IIa), (IIb), (IIc), (IIIa), (IIIb), (IIIc), (IIId) and/or (IIIe)defined above, as previously defined.

In a particular embodiment, the treatment process aims to prevent thesigns of skin ageing.

Preferably, the treatment process aims to treat the signs of skinageing.

In a particular embodiment, it also relates to a process for cosmetictreatment of the skin intended to prevent and/or treat ageing,comprising at least one step which consists in applying to skinexhibiting signs of skin ageing at least one composition comprising acompound of formula (I) as defined previously.

In particular, the process according to the invention aims to improvethe radiance and/or the uniformity of the complexion; to improve theradiance and/or the transparency of the skin; to improve the softness,the suppleness and/or the elasticity of the skin and/or the tonicity ofthe skin and/or the firmness of the skin; and/or to prevent and/orreduce wrinkles and/or fine lines.

In particular, the cosmetic treatment process aims to maintain and/orstimulate the moisturization and/or combat the drying out of the skin,and/or to maintain the barrier function of the skin.

In a particular embodiment, the compounds of formula (I), and inparticular the compounds of formulae (IIa), (IIb), (IIc), (IIIa),(IIIb), (IIIc), (IIId) and/or (IIIe) defined above, are in particularuseful as agents for combating the signs of ageing, in particularchronobiological ageing, of the skin.

The present invention also relates to the use of at least one compoundof formula (I), and in particular the compounds of formulae (IIa),(IIb), (IIc), (IIIa), (IIIb), (IIIc), (IIId) and/or (IIIe) definedabove, a salt thereof, or a solvate thereof, for preparing a compositionintended for combating the signs of ageing, in particularchronobiological ageing, of keratin materials such as the skin. It alsorelates to the use of at least one compound of formula (I) as definedabove, in a cosmetic composition comprising a physiologically acceptablemedium, as an agent intended for combating the signs of ageing ofkeratin materials such as the skin, and/or as moisturizing agents forkeratin materials such as the skin.

The present invention also relates to the use of a compound or of acomposition according to the invention for combating the signs ofageing, in particular chronobiological ageing, of the skin, and/or forimproving the moisturization of the skin.

The compounds or compositions according to the invention may be inparticular intended for correcting all skin re-epithelializationdisorders.

In a particular embodiment, the compounds or compositions according tothe invention are particularly suitable for combating the signs ofchronobiological ageing of the epidermis.

During chronobiological ageing, the thickness of the epidermis becomesreduced, the cell divisions decreasing in number. By facilitating cellmultiplication, in particular epidermal cell multiplication, theregeneration of the epidermis is facilitated and the skin has a youngerappearance.

In a particular embodiment, the compounds or compositions according tothe invention are in particular intended for preventing or reducingwrinkles and fine lines, and/or thinning of the skin and/or the flaccidand/or withered skin appearance. The present invention thus also relatesto the use of at least one compound according to the invention in acosmetic composition for preventing or reducing wrinkles and fine lines,and/or thinning of the skin and/or the flaccid and/or withered skinappearance.

The invention is illustrated in greater detail by the followingnon-limiting examples.

EXAMPLES Example 1: Synthesis of Compounds 2, 3, 4 and 5

Synthesis of Compound 2

Compound 1 ([34010-29-2]/[267235-22-3]) is described for example by Mataet al., Carbohydr. Res. 1992, 225, 159-61.

K₂CO₃ (2.12 g, 15.37 mmol) is added to a solution of compound 1 (3 g,7.69 mmol) in methanol (50 ml). The reaction mixture is stirred for 16 hat room temperature, and then adjusted to pH 4 with a 4 N aqueous HClsolution. After filtration, the filtrate is evaporated to dryness. Theresidue is purified by silica gel chromatography (dichloromethane/MeOH10:1) to give the compound 2 (white solid, 1 g, yield=59%). The ¹H/¹³CNMR spectra and the mass spectrometry are in accordance with theexpected structure.

Synthesis of Compound 3

N,N-dimethylacetoacetamide E2 (1.40 ml, 8.0 mmol) is added dropwise to asolution of D-xylose E1 (1 g, 6.7 mmol) in water (2.0 ml). Sodiumhydroxide (1.33 g in water at 30%) is then added dropwise whilemaintaining the temperature below 35° C. The reaction mixture is stirredfor 45 min at 50° C., and then left to return to room temperature for 2h 30. Butanol (1.52 g) and 37% HCl (1.41 g) are added (pH 1). After theaddition of ethyl acetate (2.5 ml), the mixture is stirred for 30 minand then left to separate out. The operation is repeated with theaddition of dichloromethane (2.5 ml). The residual aqueous phase istreated with 200 mg of vegetable black, and stirred for 15 min. Theproduct is filtered through celite and rinsed with water. The filtrateobtained is neutralized to pH 10, and then concentrated under vacuum.The inorganic salts are precipitated by addition of ethanol and thenfiltration and concentration, and then again by addition of acetone. Thefiltrate obtained is then purified by silica gel chromatography(dichloromethane/MeOH 95:5 to 85:15). The residue obtained isprecipitated from dichloromethane, filtered, washed with diisopropylether, then recrystallized from ethanol and dried under vacuum to givethe compound 3 (white solid, 144 mg, yield=10%).

Synthesis of Compound 4

Sodium hydroxide (35% in water, 0.45 ml) is added to a solution ofL-rhamnose E3 (1 g, 5.5 mmol) in N,N-dimethylacetoacetamide E2 (2.40 ml,13.7 mmol). The reaction mixture is stirred for 1 h at 60° C., and thenleft to return to room temperature and diluted with water. The mixtureis stirred for 30 min with a Dowex 500WX2-200 acid resin and thenfiltered. The aqueous phase is extracted 4 times with dichloromethane,and then concentrated under vacuum. The residue is purified by silicagel chromatography (EtOAc/MeOH 9:1). The product obtained is dissolvedin water, washed once with dichloromethane (DCM), purified with animalblack and then filtered through celite. The filtrate is rewashed twicewith DCM and the aqueous phase is concentrated under vacuum. After theaddition of ethanol, the precipitate formed is filtered off, then thefiltrate is evaporated to dryness to give the compound 4 (dark greensolid, 223 mg, yield=18%).

Synthesis of Compound 5

Compound E4 is prepared according to P. Koll et al., J. Carbohydr. Chem.2000, 19(8), 1019-47.

The lactone E4 (253 mg, 1.44 mmol) is added to n-tetradecylamine (1.54g, 7.20 mmol) liquefied at 50° C. The reaction mixture is heated at 76°C. for 4 hours. After returning to room temperature, the mixture sets toa solid. It is taken up in ethyl acetate and the solid is then filteredoff and washed with ethyl acetate. The operation is repeated twice. Awhite powder is obtained in a yield of 45%.

Example 2: Demonstration of the Depigmenting Effect of the Compounds ofFormula (I) that are Suitable for Use in the Invention Protocol

The efficacy was demonstrated on the basis of the following test:

The depigmenting activity (reduction of melanin production) of compoundsof formula (I) was measured by assay in normal human melanocytes invitro as follows.

First, normal human melanocytes are cultured and distributed in amultiple-well plate.

After 24 hours, the culture medium was replaced with a medium containingthe compounds of formula (I) to be evaluated. The cells were incubatedfor 72 hours before measuring the final optical density, which measuresthe amount of melanin produced by the melanocytes. The measurement wascalibrated and the compounds were tested at 100 μM.

Various test runs were performed and the results are collated in thefollowing tables.

Results

The test results are summarized in table 1 below.

TABLE 1 % depigmentation at 100 μM Compound Run 1 Run 2 Run 3 1 24% 229% 4 15%

From these results, it emerges that the compounds of formula (I) at lowconcentration have depigmenting properties.

Example 3: Composition According to the Invention

A skin depigmenting gel is prepared. It comprises the ingredients whichfollow (in weight % relative to the total weight of the composition):

Weight % relative to the total weight Ingredients of the compositionCompound 2 3 Carbomer (sold under the name 1 Carbopol ® 981 by thecompany Lubrizol) Preserving agent qs Water qs 100

The composition according to the invention applied to the skin makes itpossible to homogenize the complexion, in particular to fade out brownspots.

Example 4

An anti-ageing gel for the skin is prepared, comprising (% by weight):

compound 2 2% hydroxypropylcellulose (Klucel H from Hercules) 1%fragrance, preservative qs isopropanol 40%  water qs 100%

A similar composition is prepared with the compound 3.

This composition can be applied to the face each day, in particular forseveral weeks.

1. A process for treating keratin materials comprising the application,to said keratin materials, of at least one compound of formula (I), orof at least one cosmetic composition comprising at least one compound offormula (I) and the solvates thereof the optical, geometric, tautomericisomers thereof and the alkaline or acid, organic or mineral saltsthereof:

in which: S* denotes a monosaccharide sugar radical or denotes apolysaccharide sugar radical comprising from 2 to 5 saccharide units,each saccharide unit (the saccharide unit in the case of amonosaccharide or each saccharide unit in the case of polysaccharides)comprising one or more hydroxyl groups optionally substituted with aradical R′ chosen from: i) (C₁-C₆)alkyl; or ii) an acetyl radical; saidmonosaccharide or polysaccharide radical not being able to comprise a(hemi)acetal or (hemi)aminal function; said monosaccharide orpolysaccharide radical optionally comprising one or more amino groupsNR_(b)R_(c) with R_(b) and R_(c), which may be identical or different,representing a hydrogen atom, or an acetyl group, or a protective groupfor the amino function, such as (C₁-C₆)alkyl(thio)carbonyl; saidmonosaccharide or polysaccharide radical being connected to the rest ofthe molecule by a bond between the C₁ carbon atom of one of the sugarsof said monosaccharide or polysaccharide radical, this bond possiblybeing α or β anomeric; R represents a group chosen from: i) hydroxyl;this hydroxyl can be in the form of an alkoxide O⁻, M⁺ with M⁺representing a cation; (when R is in the form of an alkoxide, it forms,with the carbonyl in the alpha position a carboxylate function COO⁺, M⁺with M⁺ as previously defined); ii) saturated or unsaturated(C₁-C₁₈)alkoxy; iii) optionally substituted aryloxy, such as phenyloxyor phenoxy; iv) optionally substituted aryl(C₁-C₆)alkoxy, such asbenzyloxy; v) a radical (B1):

in which: R_(l) and Ro, independently of one another, denote a hydrogenatom or a methyl radical, it being understood that R_(l) and R_(o)cannot simultaneously denote a methyl radical; w=1 to 10, limitsincluded; or iv) amino —NR₁R₂ with R₁ and R₂, independently of oneanother, representing: for R: i) a hydrogen atom; ii) a (C₁-C₁₈)alkylgroup; iii) a (C₂-C₁₈)alkenyl group; iv) an aryl(C₁-C₄)alkyl groupoptionally substituted in particular with at least one hydroxyl and/orsaturated or unsaturated (C₁-C₄)alkoxy group; or v) an optionallysubstituted aryl or heteroaryl radical; for R₂: i) a hydrogen atom; ii)a (C₁-C₁₈)alkyl group; iii) a (C₂-C₁₈)alkenyl group; iv) anaryl(C₁-C₄)alkyl group optionally substituted in particular with atleast one hydroxyl and/or saturated or unsaturated (C₁-C₄)alkoxy group;v) an optionally substituted aryl or heteroaryl radical; vi) a radical(B′1):

in which: R_(h) and R_(k), independently of one another, denote ahydrogen atom or a methyl radical, it being understood that R_(h) andR_(k) cannot simultaneously denote a methyl radical; y=1 to 10, limitsincluded; or vii) a radical (B′2):

in which: i=0 or 1; R₄ represents a hydrogen atom or R₄ is chosen fromthe radicals (a1) to (a32) described below:

or R₄ can form, with R₁ and the nitrogen atom which bears R₁, asaturated heterocycle of formula A1, A2 or A3:

R₆ denotes i) a hydroxyl radical —OH; ii) an alkoxide —O⁻, M⁺ with M⁺representing a cation iii) a saturated or unsaturated (C₁-C₆)alkoxyradical; iv) a radical —NR_(f)R_(g) with R_(f) and R_(g), which may beidentical or different, representing a hydrogen atom or a (C₁-C₆)alkylgroup; or else R₁ and R₂ form, with the nitrogen atom to which they areattached, an optionally substituted heterocycloalkyl, such aspiperazino, piperidino or morpholino.
 2. The process as claimed in claim1, in which the compound(s) of formula (I) comprise(s) a sugar radicalS* which represents the monosaccharide radical chosen from glucose,galactose, mannose, xylose, rhamnose, frustose, sorbose,N-acetylglucosamine, N-acetylgalactosamine, glucosamine, galactosamine,lactose, cellobiose and maltose.
 3. The process as claimed in claim 1,in which the compound of formula (I) is chosen from the compounds offormulae (I′), (I″), (I″″), (I′a), (I″a), (I″″a) and (I′b) below:

and also the solvates thereof, the optical, geometrical or tautomericisomers thereof and the organic or mineral base or acid salts thereof,in which formulae (I′), (I″), (I″″), (I′a), (I″a), (I″″a) and (I′b): 4.The process as claimed in claim 1, in which the compound(s) of formula(I) is (are) chosen from the following compounds, and also the salts,isomers and solvates thereof:


5. A compound of formula (IIa), and also the solvates and/or isomersand/or salts thereof, for which:

in which: S*₁ denotes a monosaccharide sugar radical chosen from:D-glucose, D-galactose, D-mannose, D-xylose, D-lyxose, L-fucose,L-arabinose, D-arabinose, L-rhamnose, D-quinovose, D-fructose,L-sorbose, D-talose, N-acetyl-D-glucosamine, N-acetyl-D-galactosamine,D-glucosamine and D-galactosamine; the saccharide unit comprising one ormore hydroxyl groups optionally substituted with a radical R′_(a) chosenfrom: i) (C₁-C₆)alkyl; or ii) an acetyl radical; said monosaccharide orpolysaccharide radical not being able to comprise a (hemi)acetal or(hemi)aminal function; said monosaccharide or polysaccharide radicalbeing connected to the rest of the molecule by a bond between the C₁carbon atom of one of the sugars of said monosaccharide radical, thisbond possibly being α or β anomeric; R₃ represents a group chosen from:i) a hydrogen atom; ii) saturated or unsaturated (C₁-C₁₈)alkyl; iii)optionally substituted aryl; and iv) optionally substituted aryl(C₁-C₆);it being understood that: when S*₁ denotes a D-glucose, R′₃ cannot be amethyl or an ethyl, and R′₃ is other than a hydrogen atom when all itshydroxyl groups are substituted with an acetyl group (R′_(a)=acetyl);when S*₁ denotes a D-xylose, R′₃ cannot be a methyl or a (C₁₅-C₁₈)alkyl;when S*₁ denotes a D-galactose, R′₃ cannot be a hydrogen, and R′₃ isother than a methyl or ethyl when all its hydroxyl groups aresubstituted with an acetyl group (R′_(a)=acetyl); when S*₁ denotes aD-mannose, R′₃ cannot be a hydrogen or a methyl; when S*₁ denotes anL-rhamnose, R′₃ is other than a hydrogen atom or than a methyl groupwhen all its hydroxyl groups are substituted with an acetyl group(R′_(a)=acetyl); when S*₁ denotes an L-fucose, R′₃ cannot be a hydrogen;when S*₁ denotes a D-arabinose, R′₃ cannot be a methyl; when S*₁ denotesa D-talose, R′₃ is other than a hydrogen atom when all its hydroxylgroups are substituted with an acetyl group (R′_(a)=acetyl); when S*₁denotes an N-acetyl-D-glucosamine, R′₃ cannot be an ethyl, and R′₃ isother than a hydrogen atom when all its hydroxyl groups are substitutedwith an acetyl group (R′_(a)=acetyl); and the compounds of formula (IIa)have a molar mass of less than 800 Da and do not comprise more than 3rings in total.
 6. The compound of formula (IIa) as claimed in claim 5,in which S*₁ denotes a sugar chosen from D-glucose or D-xylose,preferentially D-glucose; and/or R′₃ represents a hydrogen atom or a(C₁-C₁₈)alkyl group.
 7. The compound as claimed in claim 5 chosen from(and/or solvates thereof and/or salts thereof):


8. A compound of formula (IIb), and also the solvates and/or isomersand/or salts thereof, for which:

with: S*₂ denoting a monosaccharide sugar radical or denotes apolysaccharide sugar radical comprising 2 saccharide units, eachsaccharide unit (the saccharide unit in the case of a monosaccharide oreach saccharide unit in the case of polysaccharides) comprising one ormore hydroxyl groups optionally substituted with a radical R′_(b) chosenfrom: i) (C₁-C₆)alkyl; or ii) an acetyl radical; said monosaccharide orpolysaccharide radical not being able to comprise a (hemi)acetal or(hemi)aminal function; said monosaccharide or polysaccharide radicalpossibly also comprising one or more amino groups NR_(b)R_(c) with R_(b)and R_(c), which may be identical or different, representing a hydrogenatom, or an acetyl group, or a protective group for the amino function,such as (C₂-C₆)alkyl(thio)carbonyl; said monosaccharide orpolysaccharide radical being connected to the rest of the molecule by abond between the C₁ carbon atom of one of the sugars of saidmonosaccharide or polysaccharide radical, this bond possibly being α orβ anomeric; R″₃ represents a group chosen from: i) a hydrogen atom; ii)saturated or unsaturated (C₂-C₁₄)alkyl; it being understood that: whenS*₂ denotes a monosaccharide, R″₃ cannot be a hydrogen or an ethyl; whenS*₂ denotes a monosaccharide in the pyranose form, R″₃ cannot be ann-butyl; and said compounds of formula (IIb) have a molar mass of lessthan 800 Da and do not comprise more than 3 rings in total.
 9. Thecompound of formula (IIb) as claimed in claim 8, in which S*₂ denotes adisaccharide; and/or the hydroxyl groups of S*₂ are not substituted;and/or R″₃ represents a hydrogen atom or a (C₂-C₆)alkyl group.
 10. Acompound of formula (IIc), and also the solvates and/or isomers and/orsalts thereof, for which:

wherein S* denotes a monosaccharide sugar radical or denotes apolysaccharide sugar radical comprising from 2 to 5 saccharide unit(s),each saccharide unit (the saccharide unit in the case of amonosaccharide or each saccharide unit in the case of polysaccharides)comprising one or more hydroxyl groups optionally substituted with aradical R′ chosen from: i) (C₁-C₆)alkyl; or ii) an acetyl radical; saidmonosaccharide or polysaccharide radical not being able to comprise a(hemi)acetal or (hemi)aminal function; said monosaccharide orpolysaccharide radical possibly also comprising one or more amino groupsNR_(b)R_(c) with R_(b) and R_(c), which may be identical or different,representing a hydrogen atom, or an acetyl group, or a protective groupfor the amino function; said monosaccharide or polysaccharide radicalbeing connected to the rest of the molecule by a bond between the C₁carbon atom of one of the sugars of said monosaccharide orpolysaccharide radical, this bond possibly being α or β anomeric;preferably, the hydroxyl groups of S* are not substituted and theoptional amino groups are free (—NH₂) or all substituted with an acetylgroup (—CO—CH₃) (R_(b)═H and R_(c)═H or acetyl); R_(l) and Ro,independently of one another, denote a hydrogen atom or a methylradical, it being understood that R_(l) and R_(o) cannot simultaneouslydenote a methyl radical; w=1 to 10; it being understood that saidcompounds of formula (IIc) have a molar mass of less than 800 Da and donot comprise more than 3 rings in total.
 11. A compound of formula(IIIa), and also the solvates and/or isomers and/or salts thereof, forwhich:

with: S*₃ denoting a monosaccharide sugar radical chosen from: D-xylose,D-fructose, L-sorbose, N-acetyl-D-glucosamine, N-acetyl-D-galactosamine,D-glucosamine and D-galactosamine; the saccharide unit comprising one ormore hydroxyl groups optionally substituted with a radical R′_(c) chosenfrom: i) (C₁-C₆)alkyl; or ii) an acetyl radical; said monosaccharide orpolysaccharide radical not being able to comprise a (hemi)acetal or(hemi)aminal function; said monosaccharide or polysaccharide radicalbeing connected to the rest of the molecule by a bond between the C₁carbon atom of one of the sugars of said monosaccharide radical, thisbond possibly being α or β anomeric; R″₁ represents a group chosen from:i) a hydrogen atom; ii) a (C₁-C₁₈)alkyl group; iii) a (C₂-C₁₈)alkenylgroup; preferably, R″₁ denotes a hydrogen atom or a C₁-C₄ alkyl group;R″₂ represents a group chosen from: i) a hydrogen atom; ii) a(C₁-C₁₈)alkyl group; iii) a (C₂-C₁₈)alkenyl group; iv) anaryl(C₁-C₄)alkyl group optionally substituted with at least one hydroxyland/or saturated or unsaturated (C₁-C₄)alkoxy group; v) an optionallysubstituted aryl or heteroaryl radical; or else R″₁ and R″₂ form, withthe nitrogen atom to which they are attached, an optionally substitutedheterocycloalkyl, such as piperazino, piperidino or morpholino; it beingunderstood that said compounds of formula (IIIa) have a molar mass ofless than 800 Da and do not comprise more than 3 rings in total.
 12. Thecompound of formula (IIIa) as claimed in claim 11 and/or solvatesthereof and/or salts thereof chosen from:


13. A compound of formula (IIIb), and also the solvates and/or isomersand/or salts thereof, for which:

with: S*₄ denoting a monosaccharide sugar radical or denotes apolysaccharide sugar radical comprising from 2 to 3 saccharide units,each saccharide unit (the saccharide unit in the case of amonosaccharide or each saccharide unit in the case of polysaccharides)comprising one or more hydroxyl groups optionally substituted with aradical R′_(d) chosen from: i) (C₁-C₆)alkyl; or ii) an acetyl radical;said monosaccharide or polysaccharide radical not being able to comprisea (hemi)acetal or (hemi)aminal function; said monosaccharide orpolysaccharide radical optionally comprising one or more amino groupsNR_(b)R_(c) with R_(b) and R_(c), which may be identical or different,representing a hydrogen atom, or an acetyl group, or a protective groupfor the amino function, such as (C₂-C₆)alkyl(thio)carbonyl; with theexclusion of the monosaccharides of 5-aminofuranose type; saidmonosaccharide or polysaccharide radical being connected to the rest ofthe molecule by a bond between the C₁ carbon atom of one of the sugarsof said monosaccharide radical, this bond possibly being α or βanomeric; R′″₁ represents a group chosen from: i) a hydrogen atom; ii) a(C₁-C₁₈)alkyl group; iii) a (C₂-C₁₈)alkenyl group; R′″₂ represents agroup chosen from: i) a (C₁-C₁₈)alkyl group; or ii) a (C₂-C₁₈)alkenylgroup; iii) an aryl(C₁-C₄)alkyl group optionally substituted inparticular with at least one hydroxyl and/or saturated or unsaturated(C₁-C₄)alkoxy group; iv) an optionally substituted aryl or heteroarylradical; or else R′″₁ and R′″₂ form, with the nitrogen atom to whichthey are attached, an optionally substituted heterocycloalkyl; thepiperidine ring is excluded; it being understood that, in the case whereR′″₁ represents a hydrogen atom: when S*₄ denotes a D-galactose, R′″₂cannot be an alkyl or alkenyl group; when S*₄ denotes a monosaccharide,R′″₂ cannot be a substituted or unsubstituted benzyl group; when S*₄denotes a monosaccharide of pyranose type, R′″₂ cannot be a substitutedor unsubstituted phenyl group or a 2-benzothiazolyl group or a2-benzimidazolyl group; it being understood that, said compounds offormula (IIIb) have a molar mass of less than 800 Da and do not comprisemore than 3 rings in total; and that the following compound is excluded:


14. The compound of formula (IIIb) as claimed in claim 13, in which: S*₄denotes a disaccharide, preferably disaccharides chosen from: lactose,maltulose, palatinose, lactulose, amygdalose, turanose, cellobiose,isomaltose, rutinose and maltose; and/or the hydroxyl groups of S*₄ arenot substituted; and/or R′″₁ denotes a hydrogen atom or a C₁-C₄ alkylgroup.
 15. The compound of formula (IIIb) as claimed in claim 13 (and/orsolvates thereof and/or salts thereof) chosen from:


16. A compound of formula (IIIc), and also the solvates and/or isomersand/or salts thereof, for which:

with: S*₃ denoting a monosaccharide sugar radical chosen from: D-xylose,D-fructose, L-sorbose, N-acetyl-D-glucosamine, N-acetyl-D-galactosamine,D-glucosamine and D-galactosamine; the saccharide unit comprising one ormore hydroxyl groups optionally substituted with a radical R′_(c) chosenfrom: i) (C₁-C₆)alkyl; or ii) an acetyl radical; said monosaccharide orpolysaccharide radical not being able to comprise a (hemi)acetal or(hemi)aminal function; said monosaccharide or polysaccharide radicalbeing connected to the rest of the molecule by a bond between the C₁carbon atom of one of the sugars of said monosaccharide radical, thisbond possibly being α or β anomeric; R″₁ represents a group chosen from:i) a hydrogen atom; ii) a (C₁-C₁₈)alkyl group; iii) a (C₂-C₁₈)alkenylgroup; i=0 or 1; R₄ represents a hydrogen atom or R₄ is chosen from theradicals (a1) to (a32) described below:

or R₄ can also form, with R″₁ and the nitrogen atom which bears R″₁, asaturated heterocycle of formula A1, A2 or A3:

R₆ denotes i) a hydroxyl radical —OH; ii) an alkoxide —O⁻, M⁺ with M⁺representing a cation; iii) a saturated or unsaturated (C₁-C₆)alkoxyradical; or iv) a radical —NR_(f)R_(g) with R_(f) and R_(g), which maybe identical or different, representing a hydrogen atom or a(C₁-C₆)alkyl group; and it being understood that said compounds offormula (IIIc) have a molar mass of less than 800 Da and do not comprisemore than 3 rings in total.
 17. The compound of formula (IIIc) asclaimed in claim 16, for which the hydroxyl groups of S*₃ are notsubstituted; and/or R″₁ denotes a hydrogen atom or a C₁-C₄ alkyl group;and/or R₆ denotes a hydroxyl, ethoxy or NH₂ group; and/or i=0 and R₄represents a hydrogen atom or a radical chosen from the radicals (a1) or(a5) or (a16) below:


18. A compound of formula (IIId), and also the solvates and/or isomersand/or salts thereof:

with: S* denoting a monosaccharide sugar radical or denotes apolysaccharide sugar radical comprising from 2 to 5 saccharide units,each saccharide unit (the saccharide unit in the case of amonosaccharide or each saccharide unit in the case of polysaccharides)comprising one or more hydroxyl groups optionally substituted with aradical R′ chosen from: i) (C₁-C₆)alkyl; or ii) an acetyl radical; saidmonosaccharide or polysaccharide radical not being able to comprise a(hemi)acetal or (hemi)aminal function; said monosaccharide orpolysaccharide radical optionally comprising one or more amino groupsNR_(b)R_(c) with R_(b) and R_(c), which may be identical or different,representing a hydrogen atom, or an acetyl group, or a protective groupfor the amino function, such as (C₂-C₆)alkyl(thio)carbonyl; saidmonosaccharide or polysaccharide radical being connected to the rest ofthe molecule by a bond between the C₁ carbon atom of one of the sugarsof said monosaccharide or polysaccharide radical, this bond possiblybeing α or β anomeric; R″₁ represents a group chosen from: i) a hydrogenatom; ii) a (C₁-C₁₈)alkyl group; iii) a (C₂-C₁₈)alkenyl group; i=0 or 1;R₄ represents a hydrogen atom or R₄ is chosen from the radicals (a1) to(a32) described below:

or R₄ can also form, with R″₁ and the nitrogen atom which bears R″₁, asaturated heterocycle of formula A1, A2 or A3:

R₆ denotes i) a hydroxyl radical —OH; ii) an alkoxide —O⁻, M⁺ with M⁺representing a cation; iii) a saturated or unsaturated (C₁-C₆)alkoxyradical; or iv) a radical —NR_(f)R_(g) with R_(f) and R_(g), which maybe identical or different, representing a hydrogen atom or a(C₁-C₆)alkyl group; and it being understood that: in the case where R″₁represents a hydrogen atom and when S* denotes a monosaccharide ofpyranose type, R₆ cannot be a methyl or a hydroxyl group; and saidcompounds of formula (IIId) have a molar mass of less than 800 Da and donot comprise more than 3 rings in total; and that the following compoundis excluded:


19. The compound as claimed in claim 18, in which: the hydroxyl groupsof S* are not substituted; and/or R″₁ denotes a hydrogen atom or a C₁-C₄alkyl group; and/or R₆ denotes a hydroxyl, ethoxy or NH₂ group; and/ori=0 and R₄ represents a hydrogen atom or a radical chosen from theradicals (a1) or (a5) or (a16) below:


20. A compound of formula (IIIe), and also the solvates and/or isomersand/or salts thereof, for which:

S* denotes a monosaccharide sugar radical or denotes a polysaccharidesugar radical comprising from 2 to 5 saccharide units, each saccharideunit (the saccharide unit in the case of a monosaccharide or eachsaccharide unit in the case of polysaccharides) comprising one or morehydroxyl groups optionally substituted with a radical R′ chosen from: i)(C₁-C₆)alkyl; or ii) an acetyl radical; said monosaccharide orpolysaccharide radical not being able to comprise a (hemi)acetal or(hemi)aminal function; said monosaccharide or polysaccharide radicalpossibly also comprising one or more amino groups NR_(b)R_(c) with R_(b)and R_(c), which may be identical or different, representing a hydrogenatom, or an acetyl group, or a protective group for the amino function,such as (C₂-C₆)alkyl(thio)carbonyl; said monosaccharide orpolysaccharide radical being connected to the rest of the molecule by abond between the C₁ carbon atom of one of the sugars of saidmonosaccharide or polysaccharide radical, this bond possibly being ralR″₁ represents a group chosen from: i) a hydrogen atom; ii) a(C₁-C₁₈)alkyl group; iii) a (C₂-C₁₈)alkenyl group; R_(h) and R_(k),independently of one another, denote a hydrogen atom or a methylradical, it being understood that R_(h) and R_(k) cannot simultaneouslydenote a methyl radical; y=1 to 10; and it being understood that saidcompounds of formula (IIIe) have a molar mass of less than 800 Da and donot comprise more than 3 rings in total.
 21. The compound of formula(IIIe) as claimed in claim 19, in which: the hydroxyl groups of S* arenot substituted and the optional amino groups are free (—NH₂) orsubstituted with an acetyl group (—CO—CH₃) (R_(b)═H and R_(c)═H oracetyl); and/or y is between 1 and
 5. 22. A compound of formula (I) asdefined in claim 1, in which:

S* denotes a monosaccharide, and R represents an amino group —NR₁R₂ withR₁ and R₂, independently of each other, representing: i) a hydrogenatom; or ii) a (C₁-C₁₈)alkyl group.
 23. A compound of formula (I′b) asdefined in claim 3, chosen from compound 5 and also the salts, isomersand/or solvates thereof:


24. A process for synthesizing the compounds of formula (I) as definedin claim 5 according to scheme (1) below:

comprising the following steps: step 1a: reaction of a monosaccharide ora polysaccharide of formula (IV) with Meldrum's acid (V) to givecompound (VI) bearing a sugar unit; step 2: hydrolysis of compound (VI)to give a C-glycoside acid compound (II¹); step 3: reaction of the acid(II¹) either with an alcohol R_(r)—OH to give the ester compounds offormula (II²) by esterification, or with an amine R_(r1)R_(r2)NH to givethe amide compounds of formula (III) by N-acylation/amidation; oralternatively comprising: step 1b: production of the amide compounds offormula (III) via a reaction of Lubineau type (step 1b) between themonosaccharide or the polysaccharide of formula (IV) and anacetoacetamide compound of formula (VII), in the presence of a mineralbase.
 25. A process for synthesizing the compounds of formula (I) asdefined in claim 1 and compounds of formula (I′b)

and for which A denotes a hydrogen atom and the sugar is in furanoseform according to scheme (2) below:

comprising the following step s: step 1: reaction of a monosaccharide ora polysaccharide of formula (IV) with Meldrum's acid (V) to give alactone intermediate fused with a sugar unit in furanose form NR(VIII);step 2a: hydrolysis of compound (VIII to give a C-glycoside acidcompound (II¹) in furanose form or opening of the lactone (VIII) inaqueous basic medium to give a C-glycoside acid compound (II¹) infuranose form; step 2b: opening of the lactone compound (VIII) with analcohol R_(r)—OH, to give a C-glycoside ester compound (II²) in furanoseform or opening of the lactone (VIII) with the alcohol R_(r)—OHdeprotonated beforehand with a strong base to form the correspondingalkoxide; step 2c: opening of the lactone compound (VIII) with an amineR_(r1)R_(r2)NH to give a C-glycoside amide compound (III¹) in furanoseform.
 26. The use of compound (I) as claimed in claim 1 for the cosmetictreatment of keratin materials, in particular the skin.
 27. Acomposition comprising, in a physiologically acceptable medium, at leastone compound of formula (I) as claimed in claim
 1. 28. The cosmetictreatment process as claimed in claim 1 for depigmenting, lighteningand/or bleaching keratin materials, especially facial and/or bodilyskin, and/or for preventing, reducing and/or treating an impairment inthe complexion of the skin or of the complexion of semi-mucousmembranes, comprising at least one step which consists in applying tofacial and/or bodily skin at least one composition comprising at leastone compound of formula (I).
 29. The use of compound (I) as defined inclaim as an agent for bleaching, lightening and/or depigmenting keratinmaterials, in particular the skin.